Sonic Blast (Game Gear)

Sonic Blast is the last Sonic game for the Game Gear. It's essentially Sonic & Knuckles with Sonic 3D Blast's pre-rendered graphics, but lacking in speed and with the screen crunch problems of Sonic 2 Game Gear magnified tenfold. The game was developed for the Japanese Kid's Gear brand aimed at young children (in fact, it was the very last game released for the system in that region), explaining the short length and simplicity.

Tec Toy later released a Master System port in 1997 exclusively for Brazilian markets which, while resolving some of the screen crunch issues, still manages to be worse overall for the lack of effort in optimizing the game for the platform.

Sub-Pages#

Prototype Info Bugs

Unused Graphics#

Present in the graphics for Sonic is this unused animation of the Strike Dash ability, which was in Sonic Chaos and Sonic Triple Trouble. All that remains of this move is this animation, which is stored with a vastly different object palette than used in the final game. (The above sprite animation was given a proper palette for visual clarity.)

Unused graphic of the final boss arm pointing down.

Level Select#

In the Game Gear version, press Up (×3), Down (×3), 1, 2, 1, 2, Start at the title screen. On Master System, it is impossible to access this screen without using PAR code 00D140:FF since both the 1 and Start buttons share the same function (starting the game).

Unused Text#

A build date is present at 0xC0:

GG SONIC 96     
      Ver E3 ROM
1996/05/01 @SEGA
/Aspect Co.,Ltd

The mention of E3 makes this an old leftover. It's also present in every available prototype build.

The real build date is very likely September 7, 1996.

Error Handler#

All of the 8-bit Sonic titles developed by Aspect contain a generic error handler routine at ROM 70. While the other games' routines consist of some variation on "print an error message and reset", the Sonic Blast handler simply freezes the game by going into an infinite loop. Since the game doesn't call this routine and the Z80 has no hardware error trapping, this code will only execute in the extremely unlikely event that a bug coincidentally causes the game to jump directly into it.

Partially-Unused Music#

The music used for the opening cutscene lasts 31 seconds, but only the first 6 seconds are heard in-game. Use PAR code 00D131:01 when booting to freeze the game so as to let the song play out in its entirety.

Regional Differences#

International Game Gear	Japanese Game Gear

The game was known as G Sonic in Japan, so the title screen reflects this. The title screen animation is also different, with the international version simply having the Sonic Blast logo shifting onto the screen, while the Japanese version has a ring move from left-to-right before the G Sonic logo quickly moves onto the screen and changes the ring to a G. The logo was also changed in the credits.

It should be noted that the ROM is identical across the world, so this difference only depends on the region of the Game Gear you're playing on. It can be changed by setting value $D13F to 01.

References#