Sonic the Hedgehog (Sega Master System, Game Gear)

Sonic the Hedgehog
Developer: Ancient Publisher: Sega Platforms: Sega Master System, Game Gear Released in JP: December 28, 1991 Released in US: October 25, 1991 (Master System), December 1991 (Game Gear) Released in EU: October 25, 1991 (Master System), December 1991 (Game Gear) This game has hidden developer credits. This game has hidden development-related text. This game has unused enemies. This game has unused graphics. This game has unused music. This game has unused sounds. This game has regional differences. This game has a development article This game has a prototype article This game has a prerelease article This game has a bugs page This game has a Data Crystal page

The 8-bit ports of Sonic the Hedgehog scaled down the Genesis game and included the all-new Bridge, Jungle, and Sky Base (not to be confused with Sky Chase) Zones. Given the limitations, it isn't too bad.

Although they're mostly the same content-wise, the Game Gear version has some unused sprites the Master System version doesn't, and vice-versa. The Game Gear's smaller screen also meant that things had to be scaled down, resulting in the Green Hill boss being laughably easy.

The Master System version also holds the distinction of being the last game released for the console in North America.

Sub-Pages

Development Info

Prototype Info

Prerelease Info

Bugs

Unused Graphics

Level Art

Artwork	Name	Description
	Green Hill Totem Pole	Used in the Master System version, but not the Game Gear one.
	Green Hill Corner Tile	An unused corner piece.
	Bridge Zone Tiles	A spring in front of checkerboard, and a pole in front of some sky tiles. The bridges in this Zone are never high enough to hit sky level.
	Jungle Zone Spring	A spring not set on grass. Probably intended for Act 2.
	Labyrinth Pillars	Some unused big and small pillar tiles! These were created specifically for the 8-bit versions, and have no equivalent in the Genesis version.
	Sky Base Tiles	A chain facing southeast and an unused cannon facing northeast.
	Sky Base 3 Tiles	Some unused slopes, and what appear to be laser turrets. The latter tiles are not in the Game Gear version.

(Source: GoldS, Sonic Retro)

Objects

Artwork	Name	Description
	Ground Segment	Appears amongst the object tiles for Bridge Zone. It almost looks like the top is melted.
	Door?	Appears amongst the object tiles for Labyrinth Zone. Perhaps it was intended to be a switch-operated door, like the ones in the Genesis version?
	Unused Newtron	An equivalent of the red-eyed Newtron's flying animation from the Genesis version, found in Green Hill's tileset in the VRAM. Despite always having red eyes in the 8-bit versions, they only ever act like the yellow-eyed ones from the Genesis version, and are only found in Jungle Zone at that. Master System version only.
	Shield	May be an early shield animation. Game Gear version only.
	Unused Enemy	Graphics for the enemy Batbrain appear among the Green Hill objects, and were probably meant to be used in the caves of Act 2. The Genesis version uses them in Marble Zone, not present in either 8-bit port. Game Gear version only.

(Source: Sonic Retro)

Title Screen

Artwork	Name	Description
	"PRESS BUTTON" A	This goes unused in the Master System version, as it simply reads "PRESS BUTTON". Perhaps the prompt was meant to read "PRESS A BUTTON"? This is used in the Game Gear version though, as that reads "PRESS START BUTTON".
	Ancient	Ancient handled the 8-bit ports of Sonic 1 and were evidently going to credit themselves on the title screen with the text "©SEGA/Ancient 1991". In the end, though, only Sega received credit. Notably, this graphic appears in a prerelease screenshot of the title screen.
	1992	A 1992 copyright date, Game Gear version only. Most likely present just in case the game was delayed, since the Game Gear version came out in December 1991. Appears in place of the 1991 copyright in the American and European manuals.

(Source: Sonic Retro)

Early Credits Screen

An early version of the credits screen can be found in the Master System version at ROM offset 16AEE. The triangles in the background were replaced with yellow and blue stars in the final version.

Unused Audio

A rendition of Marble Zone's theme, present in the Master System version's ROM at offset CD0A. This and the unused Batbrain graphics (present only in the Game Gear version) suggest that Marble was intended to be included in the 8-bit ports but was cut due to time or space issues.

(Source: Kroc (Sonic Retro))

This sound echoes twice. Might have been used for an early death sound effect. This would later be used in the Game Gear and Master System versions of Sonic Spinball when grabbing a Chaos Emerald.

A heavy bubbling sound. May have had a use in Marble Zone before it was scrapped?

A sound similar to the bumper sound, but at a higher pitch. Probably based off the Genesis version, as it is the same pitch.

Sounds like an alarm. May have had a use in Scrap Brain and/or Sky Base?

(Source: Original TCRF research)

Unused Text

Developer Text

A copyright string starts at 0x3B:

Developed by (C) 1991 Ancient - S Hayashi.

Filler Text

A text string (with minor variations) used as filler in the ROM banks.

'1991 (C)Ancient. (BANK0-4)
SONIC THE HEDGEHOG
 Master System & Game Gear Version.  

'1991 (C)Ancient. (BANK8-11)
SONIC THE HEDGEHOG
 Master System & Game Gear Version.

'1991 (C)Ancient. (BANK12-15)
SONIC THE HEDGEHOG
 Master System & Game Gear Version.

(Source: Original TCRF research)

Version Differences

Master System -> Game Gear

To do: This section is WIP: add more detail, elaboration, screenshots, etc. Extremely long and in-depth video.

The 8-bit versions of Sonic 1 are mostly identical, but besides the resolution there are some differences in the Game Gear version:

• A white Sega splash screen with an animated Sonic and the trademark "Sega!" voice clip was added. This was done because the Game Gear doesn't have a logo screen incorporated into the BIOS, unlike the Master System.
• The smog clouds above Scrap Brain on the map screen were redrawn.
• The sprites for Sonic, invincibility, and shields were all redrawn to be smaller, to account for the reduced screen size.
• Most stages have altered layouts, from simply moving a few rings around to completely removing or replacing entire chunks of levels.
• Warning signs were added near spike pits and cliffs in Green Hill in the Game Gear version. Various background elements were altered as well, such as the color of the mountains and the flower animations (which are closer to the Genesis version).
• The Special Stages have different layouts in the Game Gear version. On the first "loop", the stages have a time limit of 2 minutes rather than 1.
• Due to the smaller screen, the Green Hill boss flies much lower and can be reached from the ground, making it a complete joke for some, maybe most.
• On the other hand, the Bridge Zone boss is trickier, taking place on an actual bridge rather than an island.
• Fruit appears in the background of Jungle Zone.
• In the Master System version of Jungle Zone Act 2, the screen continuously locks as Sonic travels upwards through the stage, with the bottom of the screen acting as a bottomless pit. This would naturally have been completely unfair on the Game Gear, so it was removed.
• Jungle Zone's boss takes place in a steeper arena in the Game Gear version, making the bombs harder to avoid.
• The first two Acts of Labyrinth Zone have radically different layouts between versions. Most notably, the Chaos Emerald is much easier to get:
  • In the Master System version, the Emerald is sitting in the middle of a spike pit. To get it, the player must collect an invincibility power-up a few screens below, run through a lengthy obstacle course to get to the spike pit, jump in, grab the Emerald, and jump out before the invincibility wears off.
  • In the Game Gear version, it's just... sitting there, out in the open, very near the end signpost.
• The final boss no longer enters a second phase, and attacks with three floor-mounted flamethrowers rather than a moving electric wall. The homing device was also moved from above Robotnik to the middle of the ceiling.
• The credits text has been updated to reflect the hardware.
• The end-of-Act panel prize mechanics are different between versions:
  • In the Master System version, Sonic panels are obtained by finishing an Act with a specific amount of rings, and ring panels are obtained by having a multiple of 10 rings.
  • In the Game Gear version, panel prizes appear to be random and do not seem to be influenced by the amount of rings you have. The Game Gear version also adds point bonuses to end-of-Act panels.

(Source: Original TCRF research)

Master System II BIOS

To promote the Master System II in Europe, certain releases of the system came with Sonic 1 within the BIOS. Due to space limitations in order to fit the basic BIOS functions in, the credits sequence is removed, with the game instead hanging on the final results screen with Green Hill Zone's theme playing.

Sonic Origins Plus

The version of the Game Gear ROM included in Sonic Origins Plus heavily tones down strobing effects present in Sky Base Zone Act 1, possibly so as to be courteous to players susceptible to epilepsy. This is similar to the 3DS Virtual Console rerelease that dims the strobing.

Regional Differences

Japanese Game Gear	International Game Gear

Like the Genesis game, the Japanese version removes the trademark logo.

Japanese Game Gear	International Game Gear

Shinobu Hayashi has different nicknames depending on the region. It was likely changed due to "Pinbot" also being the name of a well-known pinball game. The international versions also fix a typo in "Game Programmer".