O.K. I know the GBA is sometimes a sore point here but I have been playing wario wares which is a game based on lots of little games.It's a cool game but what I liked most was the 2 player games designed to be played on a single gba.They are simple games like jumping hurdles or pushing bricks but are played with one player on the left shoulder button and the other player on the right shoulder button.The games work with just the one button (like pressing to jump a hurdle) and are based on timing or reactions.If you can have at look at wario wares (the two player games needs to be unlocked) and anyone who can program will see how simple games become fun when played by two players.It should be fairly simple to port the games (or similar ones) onto the gp32.