Sonic the Hedgehog 2 (8-bit)/Hidden content
From Sonic Retro
- Back to: Sonic the Hedgehog 2 (8-bit).
- 1 Level select
- 2 Extra acceleration
- 3 Hidden birds in Sky High Zone
- 4 Unused content
- 5 Gimmick Mountain name
- 6 Build date
- 7 Cheat device codes
- 8 References
In the Master System version, hold + + on Controller 2 when powering on the game, and keep them held down during the opening sequence. When the title screen appears, release the buttons, then press or on Controller 1.
In the Game Gear version, hold + + during the SEGA screen and keep them held down. Then, you can press to skip the intro. Finally, on the title screen, press again when Tails blinks exactly for the third time (while still maintaining the other buttons).
Pressing and at the same time on the D-Pad will result in incredible acceleration and speed to the left. This is mainly useful in emulation (and has been extensively used in a Tool-Assisted Speedrun), while it's unfeasible on a real unmodified console.
Hidden birds in Sky High Zone
If the player locates the 1UP Monitor at the top left of Sky High Zone Act 1 and walks into the left side of the Monitor without breaking it, yellow birds will come out of the trees. The player can make more birds come out after the birds have gone off-screen by walking into the Monitor again. This can happen in both Master System and Game Gear versions.
|Some unused sprites of Tails crying. Probably meant to be used in the ending cutscene when he is rescued.|
|This animation is from Sonic 1 for the Master System, but were found in Sonic 2 for the Game Gear. While Sonic originally had this animation in the AutoDemo, it was changed for the final release.|
|Sonic's death sprite from the Master System version of Sonic 1. The final version uses an updated sprite.|
|The entire body of Arijigoku Mecha can be seen here. Normally, only its head is visible.|
|The entire body of Gachou Mecha was also drawn. Normally, only its head and neck can be seen.|
|Sonic monitor. This one isn't really unused; the player can find it hidden in a wall in Crystal Egg Zone, but the graphics are obscured. When collected, it grants a Continue.|
|Question mark monitor, possibly set to give the player a random amount of Rings or items, like in the 2-player mode of Sonic 2 for the Mega Drive.|
|Grey Sneaker monitor which might have slowed down the player, similar to the Slow sneaker in Sonic 3's Competition mode.|
|This could have been a checkpoint marker, like in the 8-bit version of Sonic 1.|
|Under Ground Zone Bricks. These were originally used for the Zone in the AutoDemo prototype.|
|The remains of Green Hill Zone-style tubes for Under Ground Zone from the AutoDemo prototype.|
|Miscellaneous Under Ground Zone tiles.|
|Under Ground Zone floating platform.|
|Sky High Zone boulder, probably meant to roll down a hill in Act 1.|
|Sky High Zone platform.|
|Sky High Zone object - probably another platform.|
|Unused Aqua Lake Zone water slide. These are fully functional if placed in Act 2, causing Sonic to slide down them like in Labyrinth Zone.|
|In the Master System version, song ID $92 is occupied by a peaceful, ethereal-sounding tune of unknown purpose that is unused. In the Game Gear version, this song was replaced with the sound effect that plays when Sonic (and Tails) looks up at the stars at the end of the credits.|
Gimmick Mountain name
Originally the level card for Gimmick Mt. Zone wasn't going to have a shortened name. Hivebrain discovered the word "Mountain" within the ROM. Due to lack of space on the screen Mountain was shortened to Mt.
Similar to other games developed by Aspect, the game's build date can be located at ROM address $C0:
MS SONIC¥THE¥HEDGEHOG.2 Ver1.00 1992/09/05 SEGA /Aspect Co.,Ltd
MS SONIC¥THE¥HEDGEHOG.2 Ver2.20 1992/12/09 SEGA /Aspect Co.,Ltd
GG SONIC¥THE¥HEDGEHOG.2 Ver1.10 1992/09/12 SEGA /Aspect Co.,Ltd
Cheat device codes
These are cheat codes that can only be accessed with game enhancer devices. Support for these codes is available in most emulators.
Official codes, Game Gear version
|012-B8D-E66||Start with 1 life.|
|052-B8D-E66||Start with 5 lives.|
|092-B8D-E66||Start with 9 lives.|
|A78-92C-19E||Invincible after 1 ring (Except on act 3).|
|026-5ED-E6E||Each ring worth 2.|
|036-5ED-E6E||Each ring worth 3.|
|046-5ED-E6E||Each ring worth 4.|
|056-5ED-E6E||Each ring worth 5.|
|066-5ED-E6E||Each ring worth 6.|
|076-5ED-E6E||Each ring worth 7.|
|086-5ED-E6E||Each ring worth 8.|
|3A7-E4C-2A2||Don't lose rings when hit.|
|3E2-E4D-3B4 + 012-E5D-E69||Start on Act 2.|
|3E2-E4D-3B4 + 022-E5D-E69||Start on Act 3.|
Pro Action Replay
Unofficial codes, Game Gear and Master System version 1.0 and 2.2
|00D3A9:15||Become Invincible After Being Hit.|
|00D299:63||Infinite Rings (Press button 1 at end of level during score totaling).|
|00D2BA:00||Keeps Time At Zero (Minutes).|
|00D2B9:00||Keeps Time At Zero (Seconds).|
|00D295:0?||Zone Select (Enable switch after the first 2 screens but before the level starts, after the level starts disable).
|00D296:0?||Act Select (Enable switch after the first 2 screens but before the level starts, after the level starts disable).
|00D502:13||Start with Glider.|
|Sonic the Hedgehog 2 (8-bit)|