A lunar lander for the original Game Boy: bring the ship down on a pad, in one piece, without much fuel to spare. Gravity is always pulling, the engine is the only thing that beats it, and fuel is the whole clock.
Put the ship down on a pad — a flat, lit stretch of ground. Everything else on the ground is unmarked and fatal, however gently you touched it. Three more things have to be true at the moment of touchdown:
English draughts (checkers) for the original Game Boy — standard rules, compulsory captures and multi-jump chains, against a built-in machine opponent.
A homebrew first-person raycaster for the original Game Boy: four randomly generated maze floors, keys and doors, grunts, bats and brutes, and three save slots.
A port of the 1983 ZX Spectrum classic to the original Game Boy: twelve eggs, ladders, hungry hens, and seed that stops the clock if you reach it first.
A homebrew pseudo-3D racer for the original Game Boy: three tracks, two rivals plus traffic, hills, bends you can see coming, and 27 lap records saved to the cart.
Asteroids, on a screen that wraps at all four edges. Turn, burn and fire, and keep breaking the rocks down until there is nothing left to hit you
Classic 10×10 battleship for the original Game Boy: a seven-ship fleet that never touches, and three AI levels up to a HARD mode that maps your ships.
Three tracks, two rivals, traffic, hills and a road that bends towards the horizon, on a Game Boy with no 3D hardware at all. GB Racer is a proper arcade racer in a 128 KB cart.
Four random maze floors, three kinds of monster and a gun, rendered in true first person on a 1989 Game Boy. FPS Dungeon shouldn't work. It does.
We kept rebuilding the same Super Game Boy border kit for every game, so we fixed its bugs, added real tests and gave it away. Here's what's in GB-SGB-Tooling.