SDLRoids is essentially an Asteroids clone, but with a few extra features, and some nice game physics. It is based on xhyperoid, which is a UNIX port of the 16-bit Windows game Hyperoid. Major changes from xhyperoid are that it's using SDL for sound and graphics, has a couple of extra powerups and that the shield behaves differently. WWW: http://david.hedbor.org/projects/sdlroids/