Prerelease:Pokémon Gold and Silver

This page details prerelease information and/or media for Pokémon Gold and Silver.

To do: Everything notable from the source code leak. EVERYTHING.

Pokémon Gold and Silver had a long development phase marked by repeated delays and a shift from Game Boy to Game Boy Color. The games went through a significant overhaul between their first reveal in 1997 and their release date, leaving traces of a very different game.

Internal Material

In April 2020, a leaked copy of the source code of Pokémon Gold and Silver was released on the internet. The source code was found to contain a sea of pre-release material detailing the development of Generation II.

Sub-Pages

96px	Sprites Early sprites, scratchpads, and even a ton of unseen Pokémon!

Unused Graphics Imakuni?

Unused Maps Touched-up maps from the Space World '97 demo and an early version of Johto.

Pokémon Statistics Turns out there was a lot of re-balancing.

Development Timeline

Development of Gold and Silver took significantly longer than Game Freak originally prepared for, which as it turns out was due to several reasons. Indeed, much of the staff was allocated to working on localizing the first two games, and the development team of Gold and Silver only had about four programmers, which was similar in size to the development team for Red and Green but with the added challenge of creating several new features for the games.

1996

• February - Development of the games begins almost immediately after the release of Red and Green.
• July - Pokémon 2 is first publicly announced.

1997

• April 1 - The Pokémon anime debuts, with Ho-Oh making an appearance near the end of the first episode.
• June - Nintendo's official Pokémon 2 page, archived in June 1997, advertises an initial release date of the end of 1997.
• September 5 - The week's issue of Famitsu reports that Pokémon 2 will be released in Fall 1997.
• November 15 - The demos for Pokémon Gold and Silver at Space World '97 are compiled.
• November 21-23 - Playable demos of Pokémon Gold and Silver debut at Space World '97. Around that time, the release date was adjusted to March 1998.
• December 16 - The "Pokémon Shock" event occurs, causing the anime to be halted and delayed for a significant amount of time, and potentially impacting development of games and merchandise.

1998

• January-March - The demos of Gold and Silver from Space World '97 are showcased at the World Hobby Fair in various locations around Japan.
• March -
  • Nintendo's official Space World '97 page advertises a revised release date of the last third of March.
  • The official Nintendo webpage for Gold and Silver announces that the games will be postponed with no definitive end date.
• May 6 - The original Japan game map featured in Space World 97, alongside all internal Pokemon designs are backed up internally. The original map is scrapped and work by now has begun on the earliest version of the Johto map.

1999

• April - The May 1999 issue of CoroCoro is released, reintroducing Gold and Silver to the public.
• April 14 - Pokémon Pinball is released in Japan, where music from Gold and Silver is featured.
• August 17 - The demos for Pokémon Gold and Silver at Space World '99 are compiled.
• August 27-29 - The games, reported to be 90% complete, are showcased at Space World '99.
• October 17 - Final build dates for the Japanese version of Pokémon Gold and Silver.
• November 21 - Pokémon Gold and Silver are released in Japan.

2000

• April 24 - Earliest known prototype for the English version of Pokémon Gold and Silver
• July 7 - Final compile date for the English version of Pokémon Gold and Silver
• October 11 - Pokémon Gold and Silver are released in North America.
• October 13 - Pokémon Gold and Silver are released in Australia.

2001

• April 6 - Pokémon Gold and Silver are released in Europe.

2002

• April 24 - Pokémon Gold and Silver are released in Korea.

Concepts

Legendary Beast

In 2014, Pokémon designer Muneo Saitō released an illustration as part of material for a then-upcoming lecture he held on character design. This undated artwork depicts a creature which shares strong similarities to Raikou and Suicune. It's then likely this designed was reworked for the final games, with elements going to the final design of two of the three legendary beasts, all of which Saitō ended up designing.

Bellossom

Bellossom's Gold and Silver artwork, which was made before the final release of the games, show that it was originally planned to have dark blue skin similar to one of its evolutionary relatives. Given how the earlier version of Bellossom found in the Space World '97 proto even shares this trait, this seems to prove that this was the original intent before it was ultimately changed. While preceding the controversy regarding Jynx's skin color, the design team possibly decided to change Bellossom's in fear it'd be seen as questionable given its Polynesian influences, though this color change could have also been made because the design team wasn't satisfied with how it looked.

Regarding in-game sprites, the color change seems to have happened somewhere after mid-June of 1999, as by the time the Space World '99 demo was compiled the sprite with blue skin and red flowers/petals had already been repurposed as Bellossom's shiny sprite. The anime's model sheet using the design with green skin was shown in a mid-April 1999 release of Corocoro Comic, and a few issues later merchandise depicting Bellossom's final green-skinned design is shown, implying that the color change probably happened soon after the artwork was finalized.

Unnamed sheep

In an early 2011 interview with @Gamer magazine, Junichi Masuda and Ken Sugimori revealed that they thought about designing a Pokémon after the first cloned sheep, Dolly, but ultimately decided against it in fear that it'd be deemed "too controversial" as a concept for a Pokémon. Given how Dolly's existence was revealed to the world on 22 February 1997, when Gold and Silver had already been worked on for a year, it's then possible they originally intended for this Pokémon to be included in those games.

While no physical description of this Pokémon was provided, it's possible this concept was never given much thought. However, if that isn't the case there is a chance that how they first envisioned this "Dolly-inspired" Pokémon to look ended up inspiring the design of either Mareep or Flaaffy, two sheep-inspired Pokémon introduced in Generation II.

(Source: Bulbanews)

Lugia

Lugia was solely designed by Takeshi Shudo, who at the time was the head writer for the Pokémon anime, as well as the scriptwriter for the second Pokémon movie, which was released in July of 1999. Indeed, as confirmed by Shudo, Lugia was commissioned for the movie, and he was quite surprised to find out that it was later included in the games. Still according to Shudo, the name "Lugia" was chosen in a large meeting where even game development staff attended, though in order to keep an element of surprise Lugia was only referred to as "Pokémon X" before its public reveal .

Lugia was then retroactively envisioned as a partner for Ho-Oh when it came to its inclusion in Gold and Silver, with an internal archive dating to June 13 of 1999 being the earliest known trace of its inclusion in the games. Additionally, in a November 2009 issue of Nintendo DREAM, game designer Morimoto Shigeki gave more details regarding Lugia's significance in Gold and Silver. In this interview, he namely said that while Ho-Oh and Lugia do not have a direct connection in the story, they were envisioned as being "[...] born in the world of Pokemon Gold and Silver, for the new feature, time system, gave us day and night cycle. Thus, they represent the sun and the moon, day and night."

1996

July

Pokémon 2 was first announced in the August 1996 issue of Corocoro Comic, with Ho-Oh being the first new Pokémon shown. Ho-Oh is described as a legendary Pokémon that "only appears before a genius who will go down in history." It features an interview with Satoshi Tajiri about the basics of the game, including that there would be a total of over 200 Pokémon, with new ways to evolve Pokémon, and that the games could connect and trade with Red and Green. The games were intended to be for Game Boy, with Super Game Boy support. There is also a hint at a froglike branched evolution for Poliwag, which appears to have been a hint at Politoed, and although Poliwhirl is the one that can evolve into Politoed it's likely they were referring to the "Poliwag line".

October

A letter sent to CoroCoro by a reader asking for the Pokémon 2 release date and what colors the games will be is answered in the "Pockemon Club" section of the November 1996 issue. The editor suggests that the games will probably release in the spring of 1997 because "development seems to have advanced considerably," but says that the colors cannot be revealed yet.

December

The Pokémon anime is announced in the January 1997 issue of CoroCoro Comic (which came out in December 1996), speculating that Ho-Oh and other elements from Pokémon 2 will be featured in the show.

1997

April

In April of 1997, an issue of the magazine MicroGroup Game Review was published, featuring an interview with Ken Sugimori as well as a cover artwork for the magazine that he made specifically for that issue. In the interview, Ken Sugimori described the cover art as taking place in a Pokémon-like, but non-Pokémon, separate world. However, two of the three "Pokémon" shown bear a resemblance to ones found in the final version of Gold and Silver, which makes sense as in Sugimori's own words his creativity would often arise from him revisiting his own works.

"Hitmontop"

MGR Cover	Space World '97 Proto	Final Game

This pink, top-inspired creature has a rather unusual appearance, sharing characteristics with both the Space World '97 version of Cleffa (color and head horn) and Hitmontop (overall theme). It’s likely this design went on to mainly inspire Hitmontop, whose design went on to undergo a quite significant revision between its conception and the final version of Gold and Silver.

"Tyranitar"

MGR Cover	6/13/99 Build	Final Game

This early version of Tyranitar is nearly identical to the design used in the final version of Gold & Silver, albeit with a few notable differences. Namely, it appears to be more bulky, have a flatter and more droopy face, smaller hollow indents on its torso, additional back spikes, and slightly different tail design. Moreover, its skin is brown instead of green, its belly beige instead of blue, and its arms and legs are pretty much identical to Nidoking’s. While Tyranitar and the rest of its evolutionary line are missing from the Space World '97 demo, an internal archive dating to June 13 of 1999 shows the earliest known trace of their inclusion in the games, with them being pretty much finalized by the time the Space World '99 demo was compiled. This, in term, seems to show that the idea for a strong late-game reptilian Pokémon was conceived quite late into development.

(Source: Enhanced and unobscured version of the cover provided by Hi-res Pokémon Art)

May

At some point in early 1997, the games' titles would be lengthened to Pokémon 2: Gold and Silver. In May, a guide called ポケットモンスター公式ファンブック (Pocket Monsters Official Fanbook) was published by Shogakukan. It contained new details about the upcoming Pokémon titles, including an interview with director Satoshi Tajiri and producer Tsunekazu Ishihara.

Story

In the interview, Satoshi Tajiri gave a few details about the games' story:

The protagonist begins collecting Pokémon when he hears rumors about a certain boy in Kanto Province who completed his entire Pokédex. That's where the story starts.

This early basic plot doesn't match anything we'd actually get to see in any playable build of the game. Indeed, the closest thing comes from the game's intro shown in the Space World '97 build of the game, where we are tasked by Professor Oak to start our journey as a Pokémon trainer in helping him "putting together a new POKéDEX."

There is also something unusual about this blurb: the official Japanese name for Kanto is カントー地方 (Kantō-chihō), which translates to "Kanto region", with the word "Kanto" written in katakana. However, it is referred to here as 関東州 (Kantō-shū), meaning "Kanto Province", with the word "Kanto" written in kanji.

Gameplay

One page of the fanbook confirms (despite having been confirmed many times before) that it is possible to trade between Gold and Silver and Generation I games.

Characters

In response to the question "Will characters such as the protagonist and trainers from the previous titles make an appearance?", Tajiri had this to say:

There's a different protagonist, but the story takes place in the same setting, so there's a strong possibility that you'll meet characters from the previous titles. You'll definitely be seeing Ash and Professor Oak again! Giovanni also left to go train in the last games, so... [laughter] Look forward to that.

Red (mistaken for Ash) and Professor Oak did, indeed, go on to appear in Gold and Silver. Meanwhile, while Giovanni appears to have originally been planned to make a return (with him being found in the Radio Tower alongside Rocket Grunts in the Space World '97 demo, as well as making an appearance as an Elite 4 member in the Space World '99 demo), he ended up being absent from the final version of the games, though much of the plot centers around his disappearance.

Pokémon

Tajiri stated that, while the number of Pokémon that would appear in the games was not yet officially decided, he wanted there to be over 100 more than before. He also mentioned that players would be able to evolve some of the Pokémon that didn't have evolutions in the previous games.

The cover of the fanbook featured official art for Donphan, Ampharos, and Slowking. These three Pokémon, along with Ho-Oh, were described in greater detail inside its pages, with screenshots of their sprites.

Donphan

Early Sprite	Space World '97 Sprite	Final Sprite

This powerful-looking new Pokémon seems like it could really pack a punch. The details are still unknown, but it looks like a Rhydon-type Pokémon, doesn't it?

This initial screenshot of Donphan appears to match the sprite used in the Space World '97 demos shown to the public the following November - however, at this point in development it apparently used a blue Super Game Boy palette, which had been changed to a brown palette by the time the demo was released. This sprite seems to have stayed fairly consistent throughout development, as even the final Gold sprite is very similar, albeit reshaded to allow for a fully-colored sprite using the Game Boy Color's capabilities.

Ampharos

Early Sprite	Recovered Sprite (from backup files)	Space World '97 Sprite	Final Sprite
	File:Pokemon Gold Silver Ampharos 1996.png

This new type of Pokémon looks as though it came from outer space. The name suggests that it might be an Electric Dragon Pokémon...? Its true nature is not yet known.

The Japanese name for Ampharos is デンリュウ (Denryū), which is a homonym for both 電流 (denryū), meaning "electric current", and 電竜 (denryū), which translates to "electric dragon". Unlike Donphan, Ampharos' sprite is unique to these scans, and offers a look at some of the changes Ampharos' design went through during development, such as having smaller horns and a shorter, rounder body. By November's Space World '97 demos, this sprite had already been replaced by completely different artwork which seems to have served as the basis for its final Gold sprite, though it appears to have been more heavily redrawn than Donphan's while also being reshaded to take full advantage of the Game Boy Color's capabilities.

This early design for Ampharos can be found in a directory of the Korean section of the April 2020 source code leak. There, the sprite is labeled as PM2F_DEN, sporting a different naming scheme from the other sprites, the abbreviation likely standing for Pokémon 2 Front Denryu.

Slowking

Secret Data on Slowking
Slowpoke, a very stupid Pokémon, was out fishing for bait when a Shellder clamped onto on its tail, causing it to evolve into Slowbro. However, it is said that, in 1 instance out of 10,000, a Shellder will clamp down on a Slowpoke's head instead of its tail. As the Shellder bites down, its essence penetrates the Slowpoke's listless brain cells, bestowing upon it extreme motivation.

Slowking has quickly become a hot topic among Pokémon collectors. How its evolution takes place is still unspecified, but it has been established that it evolves from Slowpoke!

In the final games' Pokédex entries and the anime, Slowpoke's evolution is described similarly to the above, but in gameplay Slowpoke evolves into Slowking when it is traded while holding a King's Rock. Its sprites appears to be the same as in the Space World '97 demos, which itself was almost identical to the one used in the final games.

Ho-Oh

Ho-Oh was the first of the creatures appearing in Pokémon 2 to be revealed. It's said that this legendary Pokémon will only reveal itself to a genius...

In Pokémon Crystal and Pokémon Y, Ho-Oh's Pokédex description states that "It will reveal itself before a pure-hearted trainer by shining its bright rainbow-colored wings." There is no mention of whether the pure-hearted player must also be intelligent. Additionally, no sprite was provided for Ho-Oh.

Overworld

These screenshots give a glimpse into an earlier version of the original overworld that can be seen in the Space World '97 demos, both greatly differing from the Johto region as seen in the final games.

May 1997 Fanbook	Space World '97 Demo	Final Game

This image was captioned "The starting town, Silent Hills" (this name predates the PlayStation game of the same name, which wasn't released in Japan until January 1999.) As seen in November's Space World '97 demos, Silent Hills was indeed the starting town at this point in development, and from what can be seen here its layout differs significantly from the demo's version.

• The map seems more heavily forested than the demo's version, with a large number of trees directly surrounding the buildings.
• Oak's Lab sits much closer to the water with no fence separating the two, and there's a house butting right up against it. Both of these facts suggest the town's layout may have been more compressed than the version seen in the later demo.
• The single house seen here is a small one-story building. The demo's Silent Hills contains only two-story houses.

May 1997 Fanbook	Space World '97 Demo	Final Game

The town in this image was captioned オールドシティ (Old City). Data from the Space World '97 demos shows this was a traditional-style town positioned to the northwest of Silent Hills, with a route connecting the two. Compared to Silent Hills, this map bears a much closer resemblance to the version found within the demo ROM, though there are still some visible differences.

• The Old City tileset appears to be an earlier revision than the demo's version, lacking some of its unique features such as the traditional-styled wooden doors, vertically-slatted window shutters and more detailed trees.
• The area of ground to the left of the large tower extends further north than in the demo's version of the map.
• The fence to the south is unbroken in this version. In the later demo, the third fence tile along is replaced with another signpost.

TV Gamer

Two unique screenshots from a May 1997 issue of the Weekly TV Gamer magazine feature different locations in Gold and Silver. These can also be seen in the third edition of ポケットモンスターを遊びつくす本 赤 (Pocket Monsters Play Book - Red), published on February 20, 1998.

TV Gamer May 1997	Space World '97 Demo	Final Game

The first screenshot appears to be the area just south of Old City, which is the final area seen in the playable portion of the Space World '97 demos. Quite a few differences are visible in this screenshot:

• The gate building is much smaller than the version seen in the demo.
• The ground is covered in grass and there are no fences lining the route. In the demo's version of this map, the ground is simply dirt and fences have been added.
• The pathway across the water is thinner and features a proper road leading up to the gate. In the demo's version, the water doesn't stretch as far north, the pathway is wider, and the road has been removed.
• In the demo, this is the final playable area, with the player's rival standing in front of the gate entrance - however, no characters other than the player are present in this screenshot.

TV Gamer May 1997	Space World '97 Demo	Final Game

The second screenshot appears to be from West City, an area found within the demo ROM's data.

• As with the Silent Hills screenshot above, no area exactly matching this one appears in the later version of the map, though the large building resembles the large shop found in the later version of the map.
• The paved areas have a different, diagonally-oriented pattern.
• The tileset for this area also appears to be an earlier version than the one seen in the demo, as like the Old City screenshot above it lacks some of the unique features found in the demo's version such as the glass doors.
• This area appears to be using a pink Super Game Boy palette - the version found within the demo uses a grey palette instead. The shadows of the fence are also red, suggesting the palette for this area hasn't been adjusted to display water in blue as is the case in the later demo.

(Source: Comparison screenshots provided by Helix Chamber)

June

Around the time where Nintendo's official page for 'Pocket Monsters 2' is launched, including some screenshots and information regarding the game, such as its logo.

(Source: Nintendo’s official website - June 1997.)

September

The October 1997 issue of Monthly CoroCoro Comic magazine (published in mid-September) carried an advertisement for Space World 97's Mew giveaway event, in which 100,000 players would be given the opportunity to insert their game cartridge into a machine that would upload Mew into an empty slot in their party, provided they'd received the Pokédex. The advertisement stated that this Mew could be traded to Pokémon 2.

October

In October, the November 1997 issue of monthly CoroCoro Comics showed off three new types of trainers, along with their official art, leaving the editors to speculate on what role they played and what kind of Pokémon they would use. These three were Firebreather, Schoolboy, and Lass.

November

A photo from Space World '97 showing the Silver playable demo kiosks. Some details can be made out, such as the title screen, Route 29, and the unique border for the Silver demo.

In mid-November, the December 1997 issue of CoroCoro was published, continuing on the theme of introducing three characters per issue. These characters were Kurt, a Fisherman, and a Kimono Girl. Kurt was specifically described as a non-trainer character, but his role in the game was still unknown.

In addition, the first publicly playable demos of Pokémon Gold and Silver were featured at Space World '97, a showcase event held in Tokyo from November 21-23. Attendees could try the games out for about 10 minutes (which was reduced to 5 minutes at some point), a promo video was on display, and an event guidebook was distributed.

Space World '97 Official Guidebook

The official guidebook for Space World '97 featured two full pages dedicated to Pokémon Gold and Silver. The contents of these pages are described below.

Specifications

The official guidebook described the game as a Link Cable-compatible Game Boy RPG that was scheduled to be released in the last third of March 1998, for a price of ¥3,500. It was said to be 80% complete.

The held item mechanic, new to Generation II, was introduced in the guidebook with a quote from Professor Oak himself:

Big news! It seems that some of the Pokémon set to debut in Pokémon Gold and Silver have been found to carry items themselves. What's more, I hear that there are occasions when, if the Pokémon is intelligent enough, it will use the item it's holding to give it an advantage in battle. It also appears that when you trade Pokémon with a friend, you'll also be able to exchange items. I'm sorry, but that's all the information I have right now...

The Professor also advertised a number of new Pokédex features:

I also had a hand in revising and improving the latest version of the Pokédex. Pages can now be flipped through 10 at a time, and it will even automatically search by Pokémon type - Water, Fire, Grass, etc.

Characters

The guidebook introduced the protagonist, as well as mentioning that he has an older brother. This sibling, named Ken, doesn't exist in the final games and only makes an appearance in the debug version of the Space World demos (where he can even be interacted with.)

A boy living in a certain town. He has a brother who's 3 years older. These days, his primary hobby is toying around with a hand-me-down computer that was given to him by his brother.

The rival's description follows. Interestingly, this description mentions the rival character as living in the same town as the player, which is only true in the Space World '97 demo.

The boy's rival. He lives in the same town. His appearance and personality differ from the rival in the previous games.

Pokémon

Names and official art for Ho-Oh, Slowking, Ampharos, and Donphan were published in the guidebook. No specifically new details were provided about the Pokémon.

Trainers

The guidebook also listed some of the trainers who would be opposing the protagonist, and included official artwork for each. These were Schoolboy, Lass, Firebreather, Kimono Girl, and Fisherman. It's also worth noting that this artwork of the Lass is based on the early design she sported in the Space World '97 demo, as can be seen in her hair, clothes, and even her pose.

Screenshots

Four screenshots of the overworld were included on Page 35 of the guidebook. These locations were not normally accessible in the demo, but can all be found within the ROM data for the Space World '97 demo. While the tileset and layouts seem to match, the Super Game Boy palettes assigned to each area appear to differ from the data found within the demo ROM, possibly suggesting these screenshots originate from slightly earlier in development.

Space World '97 Guidebook	Space World '97 Demo

• Compared to the previous screenshot, the pink Super Game Boy palette has now been adjusted to include one blue shade in order to allow water to display correctly. In the data found within the demo ROM, West City uses a grey palette, with the pink palette applied to High-Tech City instead.

Space World '97 Guidebook	Space World '97 Demo

• Old City appears to use a green-ish Super Game Boy palette, rather than the brown seen in both the demo and the earlier screenshot.
• A male NPC stands in front of one of the tower doors. This NPC is not present in the demo ROM.

Space World '97 Guidebook	Space World '97 Demo

• A screenshot of Font, another area which can be found within the demo ROM. In this screenshot, it seems to use a brown Super Game Boy palette; in the demo ROM's data, it's assigned an orange palette instead.

Space World '97 Guidebook	Space World '97 Demo

• The player Surfs across a stretch of ocean, avoiding newly-found whirlpools. From looking at the map data found within the demo ROM, this area is situated to the west of the Blue Forest area. In this screenshot it uses a blue Super Game Boy palette, while in the demo's data it's assigned a brown palette instead.

Space World '97 Playable Demo

At Space World '97, the Pokémon Gold and Silver demo kiosks were separated into two large rows, and players were able to choose which version they wanted to try. Playtime was limited to around 10 minutes, and when the event lasted into the evening, players returned to the game demo to find new night-exclusive Pokémon. The contents of the demo are described below. The ROMs have since been acquired, and you can find the main article here.

Space World '97 Promotional Video

Footage of the demo is interspersed with footage of a slightly different and more expansive build of the game, from a video shown at the demo. The difference between the demo and the promotional video can be noted by the Super Game Boy border. The video has the almost finalized Gold border, while the demo itself has unique borders for Gold and Silver.

Another promotional video was also apparently shown, though it doesn’t appear to have been archived. According to a fan's account, it was called Introduction to the Pokédex's New Features, and in it you got to see a Skarmory, Smeargle, a Snubbull, a Poliwhirl demonstrating the new weather function by using Rain Dance, as well as a Pokédex revealing (albeit in name only) Aqua, Aquaria, Animon, Unown, and Ikari. Professor Oak also made an appearance, mentioning the existence of eggs. Gendered Pokémon were also one the last thing shown, where you could view your whether your Pokémon was male or female by checking its status. One thing to note is that two different accounts refer to Snubbull as a "fairy Pokémon", which is the name of its species, but since species names weren’t programmed in this build of the game it's likely this promo video labeled it as such directly.

Pokémon

The following Pokémon were mentioned in accounts of Space World '97, but do not exist in the prototype ROM. Given how the build of the games we have available thanks to the aforementioned ROM appears to be the exact same as the one that was available at Space World '97, the following table serves as a way to give a potential explanation as to the origin of these "mystery Pokémon."

Name	Romaji	Final Equivalent	Notes
ワタコ	Watako	Jumpluff	Most likely a misspelling by the person who wrote the account, as Jumpluff's name in the demo ROM is ワタネコ (Wataneko).
エレキング	Eleking		Most likely poor recollection by the person who wrote the account, perhaps conflating Elekid (whose name in the demo ROM is エレべビー Elebaby) and Crobat (エクシング X-ing).
ネタモン	Netamon	None	This Pokémon, whose name is very similar to Ditto's Japanese name, メタモン (Metamon), could allegedly be encountered on a route. An evolution of Ditto, Animon, can be found in the prototype's files, so "Netamon" could possibly be a misspelling or misinterpretation of the name, which is supported by another account saying that Animon's name appeared in a promotional video.
ブクー	Bukū	Qwilfish	This Pokémon could allegedly be encountered at night on a route near the player's house and was described as resembling a flying squirrel. Originally assumed to be an early version of Sentret, whose final Japanese name is オタチ (Otachi), this Pokémon actually does not appear in the demo ROM and neither does any sort early iteration of Sentret or Furret. Instead, it appears that "Bukū" is a Qwilfish whose sprite had been misinterpreted and whose name had been misread, which is supported by プクー (Pukū) being an early name for Qwilfish in the prototype ROM, and by another account correctly referring to this Pokémon as "Pukū".

Border

Space World '97 B-Roll	Final Game

While the borders used in the Space World '97 demos of the game were unique, the borders of the retail game are already implemented in them. The build in the promotional footage, though, has an earlier design of the border with a few differences:

• The Poké Ball graphics are spread farther apart.
• The ridge around the screen is golden instead of blue.
• The space between "GOLD" and "VERSION" at the bottom is more significant than in the final version.

Title Screen

Space World '97 B-Roll	Space World '97

• Some footage shows the earliest known version of the Gold title screen, which boasts a copyright date of 1996. This version featured animated embers on a white background, with a stationary Ho-Oh emblazoned across the center, closely resembling the sprite seen in the final game. The title reads ポケットモンスター2 金 (Pocket Monsters 2 - Gold), with a stylized "2" partially visible behind the kanji.
• By the time of the Space World '97 demo, the title screen has changed somewhat. The stylized "2" element was removed from the logo, leaving the title as simply ポケットモンスタ 金 (Pocket Monsters Gold) as in the final version of the game, and the English "Gold Version" text is spaced differently. Some background detailing was added above and below Ho-Oh, and the animated flames were redrawn. Ho-Oh's sprite was also completely redrawn, bearing no resemblance to the final game's sprite, and was displayed in partial silhouette. Finally, the copyright text was updated with a date of 1997.

Overworld

• 
• 

Two screenshots of unknown source showing the player in different spots of Silent Hill.

Stitch	Space World '97	Final Game

Some brief footage of the player leaving Silent Hill is shown. When combined with the two aforementioned screenshots, it provided a map that was more coherent back when the layout of this build's overworld wasn't readily available to see.

Mock-up	Space World '97	Final Game

Some footage shown in Bravo TV's Pokémon reportage give us a good look at the early sprite for the Lass trainer class.

Mock-up	Space World '97

The Pokémon coverage mentioned above also gives us some shots of the player in the "Forest dungeon" which makes up the bulk of the explorable area of the demo.

Mock-up	Space World '97

An expanded view of Old City which reveals that the NPC standing in front of the tower that was seen in the guidebook screenshot was removed. It also appears that the build of the game showcased here is different to the one that leaked online as the arrangement of the houses is different.

In the footage it's also possible to see the player "jumping" over the Cuttable tree, which was likely done via the debug menu’s walk-through-walls function.

Still	Space World '97

A glimpse of the first floor of Old City's tower shown in extant footage, which here shows that one of the Monks is missing. Statues of Arcanine are set up instead of ones depicting Bellsprout or generic dragons. Arcanine is based on the mythical kirins, statues of which can be seen often in China and Japan. The sprite for these statues still exist in the Sprout Tower tileset in Crystal, albeit unused and without their bases.

Mock-up	Space World '97

In footage of the player in West, it is possible to see that in a slightly earlier build of the Space World '97 demo a Gentleman NPC could be found near the eastern entrance. This NPC can be found in the demo’s files as it is still present in the game, albeit unused.

Mock-up	Space World '97

The area in front of the gate leading to this demo's quite condensed version of Kanto. In the footage, as the player walks through the patch of grass he encounters a wild level 32 Meowth, and a battle ensues.

Battle

In the aformentioned video, a battle between the player's Blastoise and wild Meowth is shown, with quite a few differences to be seen:

• The "into battle" effect seen here matches the Poké Ball-shaped transition described in some accounts.
• Blastoise's early back sprite can be seen when in battle.
• Meowth is seen using Sand Attack on Blastoise, despite it not being able to learn this move normally.

Other additions worth noting include:

• As seen in footage from an even earlier build, the materializing effect for when a Pokémon is sent out by the player had already been programmed. In the prototype, this effect is only assigned to Hoothoot.
• Accounts note that Gust's type had been changed from Normal-type to Flying-type at this point.

Generation I	Space World '97 Video	Space World '97 Demo	Final Game (JP)

The item menu is larger than the list from Red and Green, and when opened it blanks out the battle screen behind it. There are "folders" for TMs and Poké Balls which, when opened, briefly display a "? ?" message in the description box. The functionality appears to fully work otherwise, with the ball folder opening to a selection of different types of Poké Balls. This was an early version of the Bag's "pockets" for different types of items. It's also worth noting that Mail can also be seen in the player's inventory, and its description simply says that it is a "special item".

1997 Footage	1997 Demo	Final Game

The player's battle sprite is different: the hat has a simple circle design on it, Gold's clothes are slightly different, and the colors appear to use a purple and orange palette. What appears to have been the corresponding early Trainer sprite of this design was also found within the source code leak of 2020, and can be seen here. The demo ROM uses the same palette as the earlier footage, but the trainer back sprite itself was already finalized for the demo.

December

In December 1997, CoroCoro revealed the official art for the protagonist and the rival, as well as information that was already revealed at Space World '97: descriptions for both characters, an upgraded Pokédex, Professor Oak's presence, held items, the release date and price, and the four previously seen in-game screenshots.

1998

January

Gold and Silver were playable again at the January 1998 World Hobby Fair. Only one image survives from the demo showcased at this event, showing Honooguma fighting a Metapod. Assuming that this demo contained the same content as Space World '97, this battle would have been against a wild Metapod in the forested area. This picture shows an orange-red palette, indicating that the game's own Super Game Boy palette was disabled with the X Button.

1997 Footage	Recreation

(Source: Catstorm - Discovery, @Katsu_Nagao - Original Photograph, @obskyr - Photograph Recreation.)

Additionally, the 1998 issue of the Game Boy Encyclopedia Young Selection was published in January, which featured a three-page article on Gold and Silver. This article included some previously unknown details, as well as screenshots of Game Corner games. It advertised that there were more than four different minigames, which is actually how many can be found in the Space World '97 build of the games.

One paragraph in the article also alludes to a pre-evolution for Clefairy, and another says that bug Pokemon may show up in the morning, and bird Pokemon at night, most likely hinting at the time of day where Ledyba and Hoothoot can be caught.

Border - Revisited

Space World '97 B-Roll	Game Boy Encyclopedia	Final Game

The build used for the magazine's screenshots is earlier than the Space World '97 demo, which is evident by the earlier border. Though compared to the B-roll build, the "POCKET MONSTERS" text at the top has a "2" appended to the end. It's unclear whether the build dates from before or after the B-roll build.

Slot Machine Start!

Game Boy Encyclopedia	Space World '97 Demo	Final Game

• A significant amount of the graphics are identical, save for the transition to color mode.
• The border around the slots has been connected instead of using a simple dash pattern.
• The buttons have had their shading changed.
• Golem is shaded in the final, and a pixel was removed from its eyes.
• PAY OUT was changed to PAYOUT in the final.

Card-Guessing Game

Game Boy Encyclopedia	Space World '97 Demo	Final Game

A picture of the card minigame which debuted in the Space World '97 Proto, and would later evolve into the card-guessing minigame from the final games.

• Compared to the Space World '97 demo the lights lined on the upper half of the screen have yet to be added and there's no score counter. The cards are also spread farther apart on the board and their design is different.
• In the final games the card-guessing game was changed to resemble a betting table instead of a simple card-flipping game.

(Source: Julioointment on Imgur)

February

CoroCoro covered another World Hobby Fair event on February 15th for their March issue. A photo of a player using Honooguma in battle is included, although its sprite is barely visible, only recognizable by its black ears and tail. No other new information about the games was provided or included.

Nintendo's official page for the games receives a little update, now showing an updated logo for Pocket Monsters: Gold & Silver.

(Source: Nintendo’s official website - February 1998.)

March

The games were shown once more at the March World Hobby Fair. New information about the games comes to a halt as a webpage on the official Gold and Silver site appears confirming that the games will be delayed for an unknown amount of time in order to 'power up' the games.

1999

March

Gold and Silver finally resurface in Corocoro's April 1999 issue, and are now on the Game Boy Color. A batch of screenshots are shown, as well as a few new Pokémon and reintroducing the characters and the rewritten plot. Notably, the screenshots reveal that the gender symbols had not yet been implemented on the battle screens.

Early '99 Build	Final Game

Early '99 Build	Final Game

Early '99 Build	Final Game

Interestingly, this Venusaur has the Poké Ball symbol beside it’s name, indicating that it’s a wild Pokémon the player has already caught. In the final games it isn’t possible to encounter Venusaur in the wild without hacking.

Early '99 Build	Final Game

The player fighting against Picnicker Kanami ("Kim" in the international version), which can be found on Route 35 in the final games. The trainer class Picnicker (ピクニックガール, Picnic Girl), known in Gen I as Jr. Trainer (ガールスカウト, Girl Scout), was not yet renamed at this point. It’s also worth noting that while this trainer is shown having two Pokémon, in the final games she only have one.

Space World '97 Proto	Early '99 Build	Space World '99 (Caught Pokémon)	Final Game

This Pokédex screenshot of Slowking reveals that while the layout more closely resembles the one used in the final games, a few differences still remain:

• It has the "new Pokémon under investigation" entry as a placeholder, which was already used in the Space World '97 Demo for every new Pokémon.
• Like in the Space World '97 Demo, the sprite of a Pokémon shown in their Pokédex descriptions is flipped horizontally, which is something that was carried over from Generation I. In the final games (and every subsequent game entries) the Pokédex sprites are displayed exactly how they are in battle and on their status screens.
• There is no red border between the description and the data, nor are there any sub-menu options such as listening to the cry. The Pokédex number is missing as well. The border around the screen is a plain orange bevel, as opposed to the redder line with white highlights used in later builds as well as the final games. This is akin to the way the Space World '97 demo did Pokédex data in regard to a lack of sub-options, but is shockingly a downgrade if anything.
• In the Space World '99 Gold and Silver demo, the Pokédex uses the final game's layout, but strangely enough when you catch a Pokémon and it displays its information it shows a slightly modified variant of the Gold and Silver '97 layout.

April

• Pokémon Pinball is released, featuring two tracks that share their melodies with songs in Gold and Silver: the Blue Field for Ecruteak City and Cianwood City, and the high score entry screen for credits of Gold and Silver, respectively. Gō Ichinose composed the soundtrack of Pokémon Pinball as well as a majority of Gold and Silver 's soundtrack, including the two aforementioned tracks, and used the melodies for both games.

• Nintendo's official page for the games gets a complete overhaul to reflect the progress in development, namely showing some new artwork and screenshots, as well as the finalized logos for Pocket Monsters: Gold and Pocket Monsters: Silver.

(Source: Nintendo’s official website - April 1999.)

• Coverage of the games continue in the May 1998 issue of Corocoro where it is revealed that the games are slated for a June release, with some screenshots of the game's overworld provided. The multicolored screens indicate that the games had been fully ported to the Game Boy Color (clearer version of those screenshots were posted on Nintendo's official Gold and Silver page in May). Promotional material for Pikachu's Vacation is also shown, revealing the finalized design for Hoothoot and Elekid.

Early '99 Build	Final Game

This route, which appears to be Route 30, has been changed slightly in layout, and the two female NPCs were replaced, mostly with Youngsters and Bug Catchers. The ledge which prevents progress earlier on by placing a Pokémon battle next to it is missing completely. The tile for normal Pokémon-free grass seems to have larger dark spots. Something that is also seen here is that Gold's overworld sprite is missing its bag

Early '99 Build	Final Game

This route, which appears to be Route 32, shows a few differences too:

• The water tile resembles that of Red and Green.
• The brick bridge and the water are placed awkwardly and look strange, which was fixed in the final by making the edge of the water completely straight.

Early '99 Build	Final Game

• The patch of tall grass normally found there is missing, and the rest of the ground is covered in grass instead of being barren.
• Interestingly, the top left section of the corner mountain tile has an 8×8 tile of grass, which here is used to make the transition between grass and mountains smoother. In the final games, this unique tile doesn’t exist.

Space World '97 Proto	Early '99 Build	Space World '99 Proto	Final Game

Although the Poké Mart's layout is somewhat similar to the final games, both it and the tileset still very much resemble the Space World '97 demo. The tileset ended up being almost completely redrawn for the final games. Layout differences include:

• The counter was changed from red to blue, and the case sitting on it was removed.
• The freezers were moved from in front of the back wall to inside of it.
• Both the cooler in the lower-left and foreground shelves in the lower-right were removed and replaced with more floor space.
• Interestingly, while by the Space World '99 demo the shop tilset was pretty much finalized for some the cash registers face a different way than in any other known builds, suggesting this change was just as puzzling as it was short-lived.

(Source: Nintendo’s official website)

May

The June issue of Corocoro continued to reintroduce the games as well as new Pokémon, along with a series of screenshots that have some differences. Prototype footprints can be seen on the Pokédex screens - a generic footprint with the Pokédex number written within it. A few of these were not overwritten and are still located in the final, visible in the dex entries for glitch Pokémon #252 and #254-256.

Early '99 Build	Final Game

Farfetch'd's Pokédex description was the same as it was in Red and Green.

Early '99 Build	Final Game

Clefairy uses its Pokédex entry from Blue.

Early '99 Build	Final Game

This map is most likely a section of Union Cave, but the layout and obstacle placements are significantly different:

• The wall taking up space in the center of the room was replaced by a pool of water.
• The water in the lower-left corner of the screen was placed farther down than in the final. Additionally, it lacks the shore tiles on both its right and left sides, which may be due to the fact that the right-side shore tiles resemble the cave walls.
• A light brown palette (used by the basement of the Burned Tower and the summit of Mt. Silver in the final games) is used instead of a dark purple one. Whether this palette had been developed yet or if there had been different plans for this map remains unknown.

Early '99 Build	Final Game

• The brick border tiles were redrawn to be larger and rounder for the final games.
• Because of the way the layout works, the outer borders don't use a corner brick tile yet.
• The fence tiles on the lower right don't overlap the brick borders; they just sit below them. Grass also appears underneath the fence tiles instead of stopping before them.
• A brick floor tile marks the exit from the National Park instead of a rug.
• NPC placement is completely different. The kids by the benches aren't there, and a young male and fat man NPC are visible on the right in lieu of the dark-haired woman.
• A trash can was added by the benches for the final games.

Early '99 Build	Final Game

Early '99 Build	Final Game

• The bar at the top of the screen is multicolored and shows every pocket in the bag, in addition to the one currently selected. The final games replaces this with a staid black bar that does nothing except show the menu's controls. Later Pokémon games would adopt a style similar to the early version.
• Since the navigation bar at the top was changed to show the controls, the name of the currently selected pocket was added beneath the bag.
• The entire menu switched its orientation, with the bag graphic being on the right originally, and the item list on the left.
• The menu has a light blue, patterned background instead of a dark blue one with less detail.
• The backpack's design was changed, with the cover for the large main pocket moved down, and the strap to open it removed.
• The regular items/medicine menu was moved from the small center pocket of the bag to the left pocket.
• As seen in the second screenshot, the left pocket was originally for TMs, while in the final games the right pocket is the one where TMs are stored.

June

The July issue of Corocoro introduces Lugia and its then upcoming movie, all while also showing a few screenshots of Gold and Silver.

Early '99 Build	Final Game

Early '99 Build	Final Game

An early version of Cherrygrove City which features a different arrangement of the flower patches. The dress of the female NPC also appears to be red, while in the final games it is blue.

July

The August issue of Corocoro went on to not only introduce Murkrow's final design, but more significantly to show the updated version of the PokéGear.

Early '99 Build	Final Game

The road on Route 31 ran straight into the area with Bug Catcher Wade instead of making the player take the long way around. The ledge is also impassable, meaning that you would have had to use Cut or wade through the grass in order to reach the upper half of the route. The Cuttable tree is also placed much farther down than in the final.

Early '99 Build	Final Game

The player is seen entering a Bug Catching Contest on a Monday. In the final, it's held every Tuesday, Thursday, and Saturday. Moreover, the tileset of the room is almost entirely different, and the NPC is assigned the blue palette instead of the green one.

Early '99 Build	Final Game

• The PokéGear menus were reordered to put the back button in front.
• Markers were added to the radio tuner.
• The phone icon was changed to a more recognizable cell phone design instead of a bulkier device.
• The "tuning" text was changed from ちょうせい to チューニング.

Early '99 Build	Final Game

• The PokéGear menus were reordered to put the back button in front.
• Current time can be seen in the top-right corner. It is only present on the "back" menu in the final.
• Professor Elm is not present in the contact list.
• Bug Catcher Wade speaks of his Scyther, but he doesn't have one in the final.
• The trainer class Picnicker (ピクニックガール, Picnic Girl), known in Gen I as Jr. Trainer (ガールスカウト, Girl Scout), was not yet renamed at this point in development. Furthermore, no trainer goes by the name of サトミ (Satomi) in the final.

August

Space World '99 Event

The September issue of Corocoro reveals a handful of screenshots, some of these can also be seen on a promotional flyer for Gold and Silver. Pokémon Gold and Silver were also showcased at Space World '99, held at the end of August, where it was said to be 90% complete. The ROMs have since been acquired, and you can find the main article here.

The new features being presented at the event were an even more updated Pokédex, the Link Cable's backwards compatibility, and the Gameboy Printer's printing ability.

Title Screen

August 1999 Press Screenshot	Space World '99 - Final (JP)	Palette Glitch (JP)

The title screen is very close to the final design, showing an animated Ho-Oh sprite flying through the skies. Unlike the final game, Ho-Oh's silhouette had visible highlights instead of a full silhouette. The decision to use full silhouettes had been made by the time of Space World '99. The extra detailing on the sprite is still present in the final game, but hidden by the color palette assigned to the sprite - by using a a glitch that causes Ho-Oh to be displayed with an incorrect palette, the full details of the sprite can still be seen. Conversely, the Lugia that appears on the title screen of Silver lacks these extra palette colors, suggesting that version's title screen may have been created well after the developers decided to use full silhouettes, and that Lugia was added significantly later in the game's development.

The developers seem to have been really undecided with the idea of using a silhouette, as even the B-roll build from 1996 had Ho-Oh unobscured but then using a silhouette for the Space World '97 demo.

Generation I	Space World '97 Demo	1999 Promotional Video	Final (JP)

This screenshot of the party menu shows that the rows containing HP bars and numbers were swapped.

Early '99 Build	Final Game

Two screenshots demonstrating the advantages of giving certain types of held items to your Pokémon. Interestingly, unlike in the final games, the status bar of the opposing Pokémon doesn’t disappear when the Berry is consumed and the healing effect plays out. The healing effect also appears to be slightly different.

Space World '97 Proto	Early '99 Build	Final Game

The egg is more rudimentary in design - an ordinary egg shape without any spots, as can be observed in the Space World '97 demo.

Nintendo Promotional Video

A promo video was also showcased at the Space World '99 event, and higher quality stills from this video were used in issue n°124 of Electronic Gaming Monthly US. The build of the game shown in this video appears to predate the Space World '99 itself, and judging by the fact that it uses the "shiny" Bellossom sprite as its regular sprite we can infer that this build must date from around June of 1999. Regardless, while most of the elements resemble the final, there still are notable differences:

• Ho-Oh on the title screen has its original dark purple palette, although it is difficult to see.
• Some of the Pokémon that are encountered in the wild here are impossible to encounter in the final games, namely Slowking, Ampharos, and Togepi.

Early '99 Build	Final Game

• The tall grass patches that are sprinkled along this road in the final games are missing here.
• The Hiker NPC used to be on the other side of the path in this build of the game.
• An NPC can be seen near one of the top ledge, but is missing in the final games.
• The overworld item sprite seen on the right path in the final games is missing here.

Early '99 Build	Final Game

• The water tile resembles that of Red and Green.
• The bridge is laid out differently, and appears to be longer than in the final games, with no piece of land to be seen.
• NPC placement is completely different.

Early '99 Build	Final Game

Interestingly, here the entire cave appears to be dimly lit, and the player character is surrounded by a faint halo that lights up his surroundings as he walks around. In the final games, this cave is literally pitch black, and when Flash is used it becomes fully lit up. Interestingly, the behavior shown in this video is reminiscent of how Flash works in later entries of the series.

Early '99 Build	Final Game

• The brick border tiles were redrawn to be larger and rounder for the final games.
• Because of the way the layout works, the outer borders don't use a corner brick tile yet.
• The fence tiles on the lower right don't overlap the brick borders; they just sit below them. Grass also appears underneath the fence tiles instead of stopping before them.
• The rug marking the exit from the area is missing.
• NPC placement is completely different. The kids by the benches aren't there, and a young male and fat man NPC are visible. The dark-haired woman NPC is missing entirely.

Early '99 Build	Final Game

The sprite used for Bellossom actually appears to be that of its shiny. Seeing how its official artwork that was published at the time depicts it with blue skin, it’s then likely this was its original base sprite, before being repurposed as its shiny one once the final games came out and its palette was changed. In contrast, by the time the Space World '99 demo was compiled the final color scheme was already being used.

September

The October issue of Corocoro reveals the starters, Chikorita, Cyndaquil, and Totodile. A batch of screenshots from an early 1999 build were also shown, a few of these screenshots later appearing in better quality in the November 1999 issue of Shogakukan Magazine.

Early '99 Build	Final Game

Psyduck’s footprint appears to be more elongated here compared to how it appears in the final games, the sprite looking more like the one used for its evolution, Golduck.

Early '99 Build	Final Game

Early '99 Build	Final Game

Screenshots, possibly from an even older batch, showing water tiles more resembling the ones found in Red and Green. The protagonist' overworld sprites are still missing his bag.

Early '99 Build	Final Game

Unlike in the final games, this build of the game lacks the description box found at the bottom of the screen, here making it more akin to how the menu worked in Generation I as well as in the Space World '97 build of Gold and Silver.

Early '99 Build	Final Game

Early '99 Build	Final Game

The sprite used for the Berry trees is different than the one used in the final games, here looking more like a standard tree. The sprite for said early tree was also found within the source code leak of 2020, and can be seen here.

October

Nintendo's official page for Gold and Silver was updated around October of 1999, adding more screenshots to its promotional material section, namely ones shown in the mid-May issue of CoroCoro.

(Source: Nintendo’s official website)

November

Early '99 Build	Final Game

Shown in the November 1999 issue of Shogakukan Magazine are a few unobscured screenshots shown in magazines published earlier that year. Here while Cheerygrove City’s layout appears to be the exact same as in the final games, the woman NPC was moved significantly to the left, while her dress still appears to be blue instead of red. Her dialogue is the same as in the final games.

Early '99 Build	Final Game

Around this time period, a commercial for the games was made. In this commercial, a small clip, likely from an earlier build from before August of that year, shows the protagonist's overworld sprite without its bag.