Also known as: Sonic & Tails 2 (JP) Developer: Aspect[1] Publisher: Sega[1] Platform:
Game Gear Released in JP: November 11, 1994[1] Released in US: November 15, 1994[1] Released in EU: November 1994[1]
Tiles for an unused enemy are loaded in Atomic Destroyer Zone.
(Source: Sonic Retro)
Level Art
Artwork
Zone
Description
Great Turquoise Zone
There are spikes used "inside", but this outside spike isn't.
Meta Junglira Zone
Another unused spike and a 30-degree slope.
Robotnik Winter Zone
A 45-degree slope in front of the stage background, and an outside spring.
Tidal Plant Zone
Many unused springs. The giant bubbles in this stage make most of these springs useless.
Special Stage
Several unused slope types, spikes (which don't appear in any Special Stage), and border tiles.
Unused Text
Aspect's standard header for their Sonic games is present at 0xC0:
Sonic & Tails 2
Sonic Triple Trouble
GG SONIC & TAILS
Ver 1.00
1994/07/30 @SEGA
/Aspect Co.,Ltd
GG SONIC THE HED
GEHOG Ver 1.00
1994/08/02 @SEGA
/Aspect Co.,Ltd
Debugging Features
Error Handler
This game has a generic error handler routine at 0x70 like most other 8-bit Sonic titles, but it's quite a bit more elaborate than the rest of them. Instead of blindly scribbling an error message to VRAM, it performs some fairly extensive cleanup beforehand, loads the needed font graphics and palette, then prints "ERROR" before waiting for 3 seconds and resetting.
What's more, the handler is actually purposely called this time around! When loading a new subscreen, the game uses the target subscreen variable at RAM $D143 as an index into a jump table. If the high byte of the address read from the table is 0xFF - there is a dummy entry of 0xFFFF at index 0x1A, one past the last valid entry, for this purpose - the game will jump to the error handler.
Level Select
Hold Up and power on the Game Gear. In the opening cutscene, press Start the instant Knuckles picks up the third Chaos Emerald. If timed correctly, a ring chime will play, and the level select screen will appear after choosing a character.
Regional Differences
Title Screen
Sonic & Tails 2
Sonic Triple Trouble
The title screen is almost completely different between the Japanese and international versions. In Sonic & Tails 2, Sonic and Tails run across the screen, then the game's logo comes up, stars circling around the ring. In Triple Trouble, Knuckles jumps onto the title and laughs. The Japanese version also includes both Sonic and Tails in the Big Ring, while the International version just has Sonic. It also lacks the stars.
The Japanese version also has an extra option, "3D Stage". It simply starts up the first 3D Special Stage (allowing a choice of either Sonic or Tails) and resets once it's completed. However, graphics for this menu option are still in Triple Trouble, and the option can be re-enabled with Game Genie codes 041-49E-E66 031-31E-E62.