Proto:Sonic the Hedgehog (Sega Master System, Game Gear)

This page details one or more prototype versions of Sonic the Hedgehog (Sega Master System, Game Gear).

  This prototype is documented on Hidden Palace.

To do: Access and investigate other zones. Try to import art of the respective zones from the original game.

Porting from one system to another can sometimes be tough, as seen with the Game Gear prototype of Sonic the Hedgehog.

Download Sonic the Hedgehog (Game Gear, Prototype) File: Sonic the Hedgehog (8-bit) (Prototype).zip (info)

General Differences

Proto	Final

• There is no Sega logo in the beginning, just like the Master System version.
• Act 1 of Green Hill Zone is the only playable stage by normal means. However, Act 2 can be accessed with hacking by using a hex editor and going to offset 155FE and changing C4 to B6. Also, by using level modifier codes, it's possible to play other stages, but most either crash, are empty, or are missing their art.

Proto	Final

• The map screen has misplaced points and different smoke graphics. It also uses a similar color palette to the Master System version.

Proto	Final

• Sonic is placed further right at the start of the level.
• Sonic's palette changes to a darker blue when nearing the signpost; in the final version, he becomes ever so slightly brighter.

• A strange strip appears at the top of the level briefly. Just a graphical glitch as touching it does nothing.

Proto	Final

• The invincibility stars are more similar to the Master System version. The final game has four stars.
• Sonic's sprites are nearly identical to the Master System version, with some minor palette alterations.

Proto	Final

• Various things have yet to be added to accommodate the smaller screen size, such as warning signs near spike pits.
• The level layout is slightly different compared to the other versions.

Proto	Final

• Totem poles have three heads in the prototype, while in the final, they only have two.

Proto	Final

• The mountain range has a similar hue to the Master System version.

Proto	Final

• The Game Over screen is messed up due to some tile rearrangement.
• The credits are still in the ROM. Aside from a messed-up palette, it's 100% identical to the Master System version.

Unused Graphics

Unused

Warning sign that would be used in Green Hill act 1, however it is not used in the prototype.

Proto	Final

There is a sign pointing down that is not used in the prototype, although it is used in the final version in act 2 of the Green Hill Zone, its sprites are completely different here, making much more sense with the background.

Unused Palette

Address	Palette	Description
0x6488 to 0x64A7		This palette would be used in the Special Stage, but because the game resets after passing a stage, it becomes impossible to go there. In addition, the palette has a difference from the final version, having a dark purple sky instead of dark blue.
0x64A8 to 0x64C6		This palette would be used for objects, with a curious light purple palette as the background. No stage in the game, neither in the Master System version nor in the Game Gear version, has a stage with a similar palette, which makes it a mystery which stage it was supposed to be.