We just released a Feb. 5 '89 prototype of DuckTales for the NES!
If you'd like to support our preservation efforts (and this wasn't cheap), please consider donating or supporting us on Patreon. Thank you!

Proto:Super Mario World 2: Yoshi's Island/ys romX 0

From The Cutting Room Floor
Jump to navigation Jump to search

This is a sub-page of Proto:Super Mario World 2: Yoshi's Island.

Yoshi's Island (ys romX 0) Titlescreen.png
To do:
Move info over from (and simplify) the ys_rom_0_D pages. The bulk of the info should be kept on this page and its subpages.

The ys romX 0 prototype of Yoshi's Island may look a lot like the final game, but there are many differences in presentation and gameplay, and level design.

Notably, the title screen bears the prefix "Super Mario Bros. 5" instead of "Super Mario World 2".

The header needs to be patched to make the ROM bootable: At offset 0x7FD5, replace FF FF 0B FF FF with 20 15 0B 00 00.

Gameplay Differences

There's a lot of them.

  • The timer works almost like the one from the final game, but instead of using Stars it uses tiny clock-shaped objects and if Yoshi loses some of them they cannot be re-collected. It also doesn't automatically refill when it goes below 10 and Baby Mario is on Yoshi.
  • Yoshi can't make eggs by swallowing enemies. He needs to stomp on them to make an egg that needs to be collected.
  • Yoshi is able to eat the sand that can be found in the levels, something not possible in the final version. He will also automatically use his tongue to eat any sand nearby.
  • Yoshi's movement is stiffer, taking longer to build up momentum than in the final.
  • After doing a flutter jump, Yoshi must touch the ground before being able to do another one. If the jump button is pressed again after a flutter jump, Yoshi just lifts his feet up.
  • Yoshi cannot perform a flutter if he falls off a ledge without jumping first.
  • If Baby Mario is separated from Yoshi, he falls on the ground and starts crawling instead of crying and floating in a bubble. He doesn't cry even if he is stolen by an enemy. Baby Mario's ground sprites remain in the final ROM, unused.
  • Occasionally, if Baby Mario is separated from Yoshi, a Bandit will appear from the side of the screen and try to kidnap him.
  • Eggs can be reused after they've interacted with enemies and many objects, such as the ? Clouds.
  • Spitting enemies while holding Up shoots them straight upwards. In the final version, they are shot in an arc.
  • This build supports saving progress to SRAM, but when starting a game from File 1 all the levels are automatically unlocked, a score of 40 is assigned to them (overwrites the already existing scores), the life and coin counters are set to 99, and the Dragon Coin counter is set to 50.
  • The tiles that compose the level select screen can be moved by placing the cursor on one of them, pressing X or Y, then moving the tile to the desired position (must be empty) and pressing X or Y again. This is not saved to SRAM, but it may glitch the level select screen.
  • A number of debug tools that are left unused in the final game (freeze frame, instant level clear on File 2 that also works on File 1 and File 3, and a free movement mode) are active by default in this build.
  • When 100 coins are collected, the coin counter resets to 0 and a Dragon Coin is awarded instead of a life.
  • Poochy will not give Yoshi a ride if Yoshi hops on him.
  • This build has a different score tally board from the final.
    • The final score is calculated by adding the remaining Time Points (up to 30), Flower Points (up to 40), and Beat Points (up to 30). A fourth stat, Miss Points (up to -30), is subtracted from the total, but doesn't have a clear purpose and the only known way to get it is taking damage from watermelon seeds (will always set it to -1). While this scoring system is different from the final one, the maximum score that can be obtained is the same (100).
Protos Final
Yoshi's Island Scory Tally Proto.png Yoshi's Island Scory Tally Final.png
Below is an example of the Miss Points in use. In this example, Yoshi took damage from watermelon seeds and the Time Points were restored using items:
Ys romX 0 Miss Point.png
  • In this build, the pause menu removes Yoshi and every object in the current level, writes SELECT (or PAUSE if no item is available in the slots) onscreen using rotating characters, and shows the current amount of Dragon Coins and items on the bottom. The final version uses a black background and shows PAUSE on the top, the current score and the current record for the level in the middle, then on the bottom the current amount of lives, coins, Stars, and the available items. Apart from the whole item selector flashing faster compared to the final version, its left and right sides flash in a different way from the rest. In the final version, it flashes uniformly.
At least one item
Proto Final
Yoshi's Island Pause Menu Proto.png Yoshi's Island Pause Menu Final.png
No items
Proto Final
Yoshi's Island Pause Menu NoItems Proto.png Yoshi's Island Pause Menu NoItems Final.png
  • When aiming an egg to be shot, there are a few differences:
    • The cursor will automatically lock on to enemies.
    • The egg can be powered up if the egg-tossing button is held for a couple of seconds. When the egg is powered up, it will be shot like in the final release. Otherwise, the egg will just be tossed towards whatever direction the cursor was in.
    • In the final release, if the player moves Yoshi in the opposite direction than Yoshi is facing, Yoshi will walk backwards. In this prototype, Yoshi turns around while still aiming the egg.
  • When Yoshi is being transformed, a short animation of a sprite waving a wand with an incorrect palette can be seen. This sprite is the blue-capped baby that was replaced by Baby Mario later in development.
A similar animation exists for Baby Mario too, and it can be seen in-game by using the Game Genie code EED8-AD67 (EED8-A467 for the later prototype):
Ys romX 0 & ys rom 0 D-BabyMarioMagic.png
After it finishes, Baby Mario stays still like in the image above, but resets every time lands again on Yoshi's back.
  • The world maps have a unique appearance in this build, with more color, detail, and animation.
  • The player's color of Yoshi can only be changed when a level is completed via Goal Ring, instead of being adjacent to a world's level (a purple Yoshi is able to be played outside a 5th level, for example).

Audio Differences

  • This build uses placeholder sound effects and music from Super Mario World.
  • Upon unlocking World 2-8 on a save file, the Valley of Bowser unlock sting will play and the map music will be temporarily swapped with that of Vanilla Dome. The music will continue to play until entering a level, where the regular map music will resume as normal.

Graphical Differences

Proto Final
Ys romX 0 MessageBlock.gif YI Final MessageBlock.gif

The Message Blocks have a circular shape in this build, rather than the standard blocky shape.

Proto Final
Ys romX 0 Clock.png YI Final Star.png

The collectible Stars that boost the player's countdown timer are clocks in this build.

Proto Final
Ys romX 0 Toadies.png YI Final Toadies.gif
Proto Final
Ys romX 0 LoseToadies.png YI Final LoseToadies.png

Kamek's Toadies are propeller-wearing Snifits in this build. The propeller doesn't animate in this build, but the graphics are present in the ROM.

Intro Differences

To do:
Needs translations from the ys_romx_0 build. There might be some changes from the early script.
Proto Final
Yoshi's Island (ys rom 0 D) - Intro.png YI Final IntroJungle.png

During the part where Yoshi meets Baby Mario for the first time, a beam of sunlight shining in the forest was removed in the final.

More notably, instead of the map dropping down on Yoshi's head, a wand does. This is a leftover from earlier in development, where the baby that Yoshi encountered was a blue-capped wizard/magician.

Proto Final
Ys romX Intro.png Yoshi's Island Intro Final.png

When Yoshi is walking back to the other Yoshies, it can clearly be seen that Baby Mario's diaper is blue instead of white like it is in the final. It is likely that it was like this to reflect the color of Mario's overalls in other Mario games, but in the end it was changed to white.

Other Differences

Error Messages

Apart from having a slightly different font, error messages that the game may display have minor differences from the final version:

Controller Error

Proto Final
Ys romX 0 & ys rom 0 D-ControllerError.png SMW2YI-ControllerError.png

Unlike the final game, the check is performed every time before loading the world map rather than before the Nintendo logo. This means that it's necessary to have a standard controller plugged into Port 1 and something other than a controller plugged into Port 2 to trigger it. In this prototype the music stops, but in the other one the map screen music plays at this screen. Strangely text was shifted a bit to the right in the final version.

Region Error

Proto Final
Ys romX 0 & ys rom 0 D-RegionError.png SMW2YI-RegionError.png

Word and character spacing on the second row was reduced in the final version, OR SUPER NES was split into two lines and a period was added. This prototype's screen doesn't contain NINTENDO CO., LTD.



An unused transformation where Yoshi becomes a bomb and explodes, which destroys all enemies on-screen. The graphics for this transformation still exist in the final game, where they go unused. To activate this transformation, use Pro Action Replay (PAR) code 7000B20E.

Ys romX 0 BombYoshi.gif


There are three types of controls that can be chosen in the level selection screen.

Type 1

  • Y: Extend tongue / Put enemy in mouth / Spit enemy out (no eggs) - Aim (hold) / Throw egg (release; Aim and Throw only if Yoshi carries at least one egg)
  • A: Extend tongue / Put enemy in mouth / Spit enemy out (even if Yoshi carries at least one egg)
  • B: Jump
  • L: Lock target reticule when aiming
  • R: Change target reticule when aiming

Type 2

The style closest to the final game's.

  • Y: Extend tongue / Put enemy in mouth / Spit enemy out (even if Yoshi carries at least one egg)
  • A: Aim (hold) / Throw egg (release, Yoshi throws even with no eggs)
  • B: Jump
  • L: Lock target reticule when aiming
  • R: Change target reticule when aiming

Type 3

  • Y: Aim (hold) / Throw egg (release, Yoshi throws even with no eggs)
  • A: Extend tongue / Put enemy in mouth / Spit enemy out (even if Yoshi carries at least one egg)
  • B: Jump
  • L: Lock target reticule when aiming
  • R: Change target reticule when aiming


Ys romX 0 & ys rom 0 D w1-8 Preview.png
World 1
The world of gooey blobs.
Ys romX 0 & ys rom 0 D w2-8 Preview.png
World 2
This world's plant has quite a bite!
Ys romX 0 & ys rom 0 D w3-1 Preview.png
World 3
That's a lot of turtles...
Ys romX 0 & ys rom 0 D w4-1 Preview.png
World 4
Poochy strikes back!
Ys romX 0 & ys rom 0 D w5-8 Preview.png
World 5
You've heard of lunar rabbits, now get ready for lunar ravens!
Ys romX 0 & ys rom 0 D w6-8 Preview.png
World 6
Look, it's from Baby Bowser!

Related Things

Bonus Challenges
You'll need 5 Dragon Coins to view this subpage.
Ys romX 0 Clock Item +10.png
A very different set of tools for Yoshi to utilize.
Ys romX 0-BanditHouse-Intact.png
Mini Battles
We all know why Yoshi had to quit his job as a house demolisher.
Ys romX 0 & ys rom 0 D w5-6 Preview.png
Preview Icons
Because snowmen don't sit when riding cable cars.

Level Names

All of the levels in Yoshi's Island have a name that briefly appears at the start of the level.

To do:
Add the introductive level text.
Cacti may speak Japanese, but do they speak it well?
...But does it make sense?
The translations on this page need to be proofread. If you are fluent enough in this language, please make any corrections necessary!
Notes: Spiritix will do initial translating, but needs to be double-checked for correctness.

World 1

Level Proto Translation Final (JP) Final (EN) (Official Translation)
1-1 ワンワンちゅうい コース Chain Comp Warning Course タマゴをつくって なげろ Make Eggs, Throw Eggs
1-2 パックンのもり コース Piranha Plant Forest Course きょだいワンワンちゅうい Watch Out Below!
1-3 たけうまジャンプ コース Stilts Jumping Course プチパックンのどうくつ The Cave of Chomp Rock
1-4 ムーチョのとりで コース Snifit’s Fort Course ビッグドンブリの とりで Burt the Bashful's Fort
1-5 とりアスレチック コース Bird Athletics Course ちくわゆか アスレチック Hop! Hop! Donut Lifts
1-6 トンネルめいろ コース Tunnel Maze Course たけうまにのったヘイホー Shy-Guys On Stilts
1-7 つむじとジュゲム コース Gusty and Lakitu Course さわるとふるふるワタボー Touch Fuzzy Get Dizzy
1-8 スライムボスのしろコース Slime Boss’s Castle Course ビッグスライムの おしろ Salvo The Slime's Castle

World 1-1 Duplicates

There are 19 level slots in the range 0x09-0x3B that lead to duplicates of World 1-1. Slots equal or greater than 0x44 lead to glitch levels and may crash the game.

Most of them (0x09, 0x14-0x23 and 0x2D-0x3B) have the "Yoshi's Island - Hollow Grasslands" title card also found in the final game and you can access one of these levels by using the Game Genie code DBDD-B356 for both the prototypes. These title cards use a slightly different font compared to the one of the final version:

Proto Final
Ys romX 0 & ys rom 0 D-Level 09-TitleCard.png SMW2Hollow.png

Level IDs 0x0A, 0x0B and 0x2C, that can be accessed with the respective Game Genie codes DCDD-B356, D8DD-B356 and 4ADD-B356, feature different and unique title cards:

(Translation: chess!!#5822 (first and last one))

World 2

Level Proto Translation Final (JP) Final (EN) (Official Translation)
2-1 はなちゃんとポチコース Flower and Poochie Course ノコノコとパタパタがいた Visit Koopa And Para-Koopa
2-2 やきゅうコース Baseball Course ミットさんとバットくん The Baseball Boys
2-3 テトリスブロックコース Tetris Block Course つむじくんって どんなあじ What's Gusty Taste Like?
2-4 ヘリコでGO! Go Helicopter! びっくりテレサの とりで Bigger Boo's Fort
2-5 つむじとおたまとキラー Gusties, Eggs, and Bullet Bills ジュゲムに きをつけろ Watch Out For Lakitu
2-6 ぐるぐるどうくつコース Circulating Cave Course なぞときめいろ どうくつ The Cave Of The Mystery Maze
2-7 ゆらゆらワタボーコース Swaying Fuzzies Course かべあなから ジュゲム Lakitu's Wall
2-8 ドカンめいろコース Pipe Maze Course おせおせ! つぼおばけ The Potted Ghost's Castle

World 3

Level Proto Translation Final (JP) Final (EN) (Official Translation)
3-1 ノコノコ コース Koopa Course ようこそモンキーワールド Welcome To Monkey World!
3-2 かべあなジュゲム コース Lakitu Wall Course ようきなヤリヤリダンサー Jungle Rhythm…
3-3 カウントゆかアスレチック Counting Platform Athletics ウンババのすむジャングル Nep-Enuts’ Domain
3-4 きょだいワンワン コース Giant Chain Chomp Course ゲロゲーロのすむ とりで Prince Froggy’s Fort
3-5 パタパタごろごろ コース Scattered Para-Koopa Course ジャングルのアスレチック Jammin’ Through The Trees
3-6 プクプク コース Cheep Cheep Course ハリネズミの どうくつ The Cave Of Harry Hedgehog
3-7 ジュゲム コース Lakitu Course おさるのすきな みずうみ Monkeys’ Favorite Lake
3-8 てっきゅうドスン コース Pounding Iron Ball Course ビッグパックンの どかん Naval Piranha’s Castle

World 4

The names of these levels seem to be placeholders that are supposed to briefly describe the level, though they don't really.

Level Proto Translation Final (JP) Final (EN) (Official Translation)
4-1 カベバタン Wall Smash マリオでGO!GO! GO! GO! MARIO‼
4-2 たつまき Tornado かべあなジュゲムの ちか The Cave Of The Lakitus
4-3 クルクルゆか Spinning Platform カウントゆかアスレチック Don’t Look Back!
4-4 ゴロゴロ Rumble ビッグプチプチの とりで Marching Milde’s Fort
4-5 パウスイッチ One Pause もってけ ワンワンいわ Chomp Rock Zone
4-6 カニワンワン Chain Chomp Crab プクプクがいる みずべ Lake Shore Paradise
4-7 プクプクアビスカニ Cheep Cheep Abyss Crab せんリフトでアスレチック Ride Like The Wind
4-8 キラーキシャワンワン Bullet Bills Shooting Chain Comps ビッグノコノコの おしろ Hookbill The Koopa’s Castle

World 5

World 5-7 does not have a name come up at the beginning of the level in this build.

Level Proto Translation Final (JP) Final (EN) (Official Translation)
5-1 とりやまとざんコース Bird Mountain Climbing Course ゆきの  かみなりジュゲム BLIZZARD‼!
5-2 アホーどりらっかコース Goonie Descent Course スキーリフトで GO! Ride The Ski Lifts
5-3 せんリフトアスレチック Lift Line Athletics つるつる  こおりのせかい Danger – Icy Conditions Ahead
5-4 カウントゆかとしろコース Counting Platform and Castle Course ビッグけめくじの とりで Sluggy The Unshaven’s Fort
5-5 おそらのくもコース Clouds of the Sky Course あほーどりでアスレチック Goonie Rides!
5-6 ジュゲンとリフトコース Lakitu and Lift Course おそらの くものうえで Welcome to Cloud World
5-7 せんリフトと おちるゆか Shifting Platforms Ahead
5-8 とりようさいコース Bird Fort Course ビッグキューちゃんのしろ Raphael The Raven’s Castle

World 6

Level Proto Translation Final (JP) Final (EN) (Official Translation)
6-1 ちかめいろコース Underground Maze Course きょうふの ほねあほーどり Scary Skeleton Goonies!
6-2 おばけとほのおのコース Ghost and Fire’s Course ボロドーだらけの どうくつ The Cave Of The Bandits
6-3 おばけとホネコース Ghost and Bone Course かいてんまるたアスレチック Beware The Spinning Logs
6-4 ようがんとどかんコース Lava and Banging Course ビッグカチカチの とりで Tap-Tap The Red Nose’s Fort
6-5 ようがんとどうくつコース Lava and Cave Course すご~くなが~い どうくつ The Very Loooooong Cave
6-6 てっきゅうドスン コース Pounding Iron Ball Course こわいこわい ちかのめいろ The Deep Underground Maze
6-7 つむじとテトリスブロック Gusties and Tetris Blocks すごくハードなアスレチック KEEP MOVING‼‼
6-8 てっきゅうドスン コース Pounding Iron Ball Course いよいよ クッパじょうだ King Bowser’s Castle