(Download) Free Games: TubeRoll (16k) and SpaceRace (64k)
Both games take place in a tunnel. In TubeRoll you have to collect green balls (and avoid red ones) while SpaceRace is a… race. Both games are small, very small from a disk size point of view: 4k for TubeRoll (XP version and 16k for Vista/Seven) disk and 64k for SpaceRace.
These games do not use D3D or OpenGL (I didn’t see dependencies with GL or D3D libs) so you should manage to enjoy these games on any system…