Space Duel was an Asteroids-style multiplayer game that I made in 9th and 10th grade.
The game has a reasonably good AI to play against, customizable ships and weapons, and a lot of particle effects. The game was written in Visual Basic 6, and it used DirectX 8 for graphics and for keyboard and game controller input. Each different kind of game controller had a configuration text file, so I could add more controllers without changing any code. Weapons and ships were also loaded solely from text files and bitmaps so that my friends and I could easily design custom ships and weapons.