Sonic the Hedgehog (8-bit)/Hidden content

Back to: Sonic the Hedgehog (8-bit).

1 Unused content
2 Misplaced objects
- 2.1 Bridge Zone Act 2
3 Cheat device codes
- 3.1 Game Genie
  - 3.1.1 Official Codes, Game Gear version 1.0
  - 3.1.2 Official Codes, Game Gear version 1.1
- 3.2 Pro Action Replay
  - 3.2.1 Unofficial codes (Master System)
  - 3.2.2 Unofficial codes (Game Gear)
4 References

Unused content

Art

Found by contributors here and The Cutting Room Floor.^[1]

Art	Description
	The letter A for the title screen button prompt. While used in the Game Gear version for the "PRESS START BUTTON" text it goes unused in the Master System version as the prompt simply reads "PRESS BUTTON".
	Ancient handled the 8-bit version of Sonic the Hedgehog and it looks like they intended to credit themselves on the title screen. Only Sega gets the credit in the final release.
	A 1992 copyright date found only in the Game Gear version, likely added in the event that the game could not be released in 1991. This date was used on the title screen in the North American and European manualsMedia:Sonic1 GG US manual.pdf^[2]Media:Sonic1 GG EU manual.pdf^[3].
	This graphic for the Green Hill Zone totem poles is used in the Master System version of the game, but is left unused in the Game Gear version.
	A Green Hill Zone corner tile from the Master System version, left unused on the Game Gear.
	A checkered spike from the Game Gear version of the game.
	Newtron sprites found in the Master System version of Green Hill Zone. While the enemy appears in Jungle Zone, it uses different graphics.
	Batbrain art which appears in the Game Gear version of Green Hill Zone but isn't used. It was probably meant to be in the caves of Act 2. In the 16-bit version this is a normal enemy in Marble Zone, a level not found in this version.
	This appears amongst the object tiles for Bridge Zone, in both the Game Gear and Master System versions. It almost looks like the top is melted.
	Spring in front of checkerboard pattern, and pole in front of sky tiles for Bridge Zone. The bridges in this Zone do not reach sky level. Found in both versions.
	A horizontal spring without grass present, likely meant for Act 2 of Jungle Zone. Found in both versions.
	This appears amongst the object tiles for Labyrinth Zone in both the Game Gear and Master System versions. Perhaps it was intended to be a switch-operated door, like the ones in the Mega Drive version.
	Small and big pillars for Labyrinth Zone. No pillars like these exist in the 16-bit version of the level. Found in both versions of the game.
	Slopes and laser turrets for Sky Base Zone Act 3. The laser turrets may indicate that elements of an unused final boss concept from the 16-bit version of the game were implemented and later cut. The latter tiles are not in the Game Gear version.
	Chain and unused cannon for Sky Base Zone.
	A prototype shield animation?

Audio

Music

Audio	Offset	Description
	CD0A	An 8-bit rendition of the Marble Zone music is present in the Sega Master System ROM. This and the unused sprite of Batbrain suggests that Marble Zone was possibly intended to appear in the 8-bit conversions, but was cut at some point. A ROM image with Green Hill Zone's music replaced with the Marble Zone music is available here.

Sound effects

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.^[4]

Misplaced objects

Bridge Zone Act 2

There is supposed to be a Spikes Badnik placed on the ground beneath the Point Marker in the Game Gear version of Bridge Zone Act 2, but it is erroneously placed beneath the floor. As a result, the Badnik ends up out of bounds and is never seen in normal play. The only way to see it is to use an emulator to extend the game screen and jump into the river to the right of its spawn point, as shown in the screenshot above.

Cheat device codes

These are cheat codes that can only be used with game enhancer devices. Support for these codes is available in most emulators.

Game Genie

Official Codes, Game Gear version 1.0

Code	Effect	Reference
`007-01A-3BE`	Unlimited lives.
`093-7DE-E66`	Start with 9 lives.
`053-7DE-E66`	Start with 5 lives.
`013-7DE-E66`	Start with 1 life.
`020-54A-E6E`	Rings worth 2 points.
`030-54A-E6E`	Rings worth 3 points.
`040-54A-E6E`	Rings worth 4 points.
`050-54A-E6E`	Rings worth 5 points.
`060-54A-E6E`	Rings worth 6 points.
`070-54A-E6E`	Rings worth 7 points.
`080-54A-E6E`	Rings worth 8 points.
`3A0-21C-2A2`	Never lose rings.
`003-F8C-3B7`	Timer disabled.
`2A2-86A-6E2`	Infinite Air.

Official Codes, Game Gear version 1.1

Code	Effect	Reference
`2A2-86A-6E2`	Infinite Air.
`003-8CE-5D4 + 013-88E-91A`	Start on Green Hill Zone, part 2.
`003-8CE-5D4 + 023-88E-91A`	Start on Green Hill Zone, part 3.
`003-8CE-5D4 + 033-88E-91A`	Start on Bridge Zone, part 1.
`003-8CE-5D4 + 043-88E-91A`	Start on Bridge Zone, part 2.
`003-8CE-5D4 + 053-88E-91A`	Start on Bridge Zone, part 3.
`003-8CE-5D4 + 063-88E-91A`	Start on Jungle Zone, part 1.
`003-8CE-5D4 + 073-88E-91A`	Start on Jungle Zone, part 2.
`003-8CE-5D4 + 083-88E-91A`	Start on Jungle Zone, part 3.
`003-8CE-5D4 + 093-88E-91A`	Start on Labyrinth Zone, part 1.
`003-8CE-5D4 + 0A3-88E-91A`	Start on Labyrinth Zone, part 2.
`003-8CE-5D4 + 0B3-88E-91A`	Start on Labyrinth Zone, part 3.
`003-8CE-5D4 + 0C3-88E-91A`	Start on Scrap Brain Zone, part 1.
`003-8CE-5D4 + 0D3-88E-91A`	Start on Scrap Brain Zone, part 2.
`003-8CE-5D4 + 0E3-88E-91A`	Start on Scrap Brain Zone, part 3.
`003-8CE-5D4 + 0F3-88E-91A`	Start on Sky Base Zone, part 1.

Pro Action Replay

Unofficial codes (Master System)

Code	Effect
`00D2D0:06`	Freezes The Time.
`00D246:09`	Infinite Lives.
`00D2AA:98`	Infinite Rings.
`00D2CF:00`	Infinite Time.
`00D284:09`	Infinite Continues.
`00D206:28`	Infinite Shields.
`00D208:01`	Invincibility.
`00D411:05`	Have Speed Shoes (Turn off the code to resume to normal).
`00D27F:06`	Have All Chaos Emeralds (Enable and then disable code).
`00D2EC:08`	Boss Instant Defeat.
`00D23E:??`	Level Modifier (Turn off to continue to next level). 00: Green Hill Zone 1 01: Green Hill Zone 2 02: Green Hill Zone 3 03: Bridge Zone 1 04: Bridge Zone 2 05: Bridge Zone 3 06: Jungle Zone 1 07: Jungle Zone 2 08: Jungle Zone 3 09: Labyrinth Zone 1 0A: Labyrinth Zone 2 0B: Labyrinth Zone 3 0C: Scrap Brain Zone 1 0D: Scrap Brain Zone 2 0E: Scrap Brain Zone 3 0F: Sky Base Zone 1 10: Sky Base Zone 2 11: Sky Base Zone 3 12: End Game

Unofficial codes (Game Gear)

Code	Effect
`00D2D1:06`	Freezes The Time.
`00D240:09`	Infinite Lives.
`00D2A9:63`	Infinite Rings.
`00D2D0:00`	Infinite Time.
`00D2D6:28`	Infinite Shields.
`00D209:01`	Invinciblity.
`00D412:05`	Have Speed Shoes (Turn off the code to resume to normal).
`00DC0A:02`	Have Turbo Sneakers (Only way to use them in Game Gear).
`00D279:06`	All Emeralds (Enable and then disable code).
`00D238:??`	Level Modifier (Turn off to continue to next level). 00: Green Hill Zone 1 01: Green Hill Zone 2 02: Green Hill Zone 3 03: Bridge Zone 1 04: Bridge Zone 2 05: Bridge Zone 3 06: Jungle Zone 1 07: Jungle Zone 2 08: Jungle Zone 3 09: Labyrinth Zone 1 0A: Labyrinth Zone 2 0B: Labyrinth Zone 3 0C: Scrap Brain Zone 1 0D: Scrap Brain Zone 2 0E: Scrap Brain Zone 3 0F: Sky Base Zone 1 10: Sky Base Zone 2 11: Sky Base Zone 3 12: End Game