Dr. Ludos, creator of the Game Gear title Dangerous Demolition, has created what he's calling the first "Super Game Boy exclusive" video game.
Entitled DMG vs. Super Game Boy, this homebrew offering "unlocks a hidden feature of the Super Game Boy, that no game ever used before: the ability to display and control Super NES sprites over the GB screen contents," according to its developer.
A top-down fighting game, you assume the role of the original 1989 Game Boy model, and you use your extendable arms to smash enemies.
Dr. Ludos explains what makes this release so special:
"As you'll notice, all the enemies in this game are very colorful, more than anything the Game Boy Color or Super Game Boy can usually display. It's because they are Super NES sprites, overlaid on top of the Game Boy screen contents."
While this feature was developed by Nintendo for the Super Game Boy hardware – and is even referenced in early versions of its development manual – it was listed as "prohibited" in the final release and disabled inside the Super Game Boy's BIOS.
Why? Well, as Dr. Ludos explains, the feature is flawed:
"The SNES sprites are constantly flickering. Up to 24 SNES sprites can be controlled at once by the SGB, but they will always be displayed once every 2 frames at best. That's why they look like "translucent" in the screenshots. I guess that the developers of the Super Game Boy never managed to have this feature running smoothly without flickering, so they simply disabled it when the device was commercially released."
However, thanks to the efforts of a hacker named Nenson Dubois, this feature has been re-enabled, and Dr. Ludos has put it to good use in DMG vs. Super Game Boy.
You can download the game free of charge from here, but you'll need either a Super Game Boy 1 or 2, a GB flashcart and a SNES or Super Famicom to run it. You can also use the SD2SNES / FXPakPro flash cart, as it can emulate a Super Game Boy. If you don't have original hardware, you can emulate it.