If anyone remembers the old Atari game Tempest, there's an excellent and astonishingly small by modern standards (about a 5mb download) freeware clone of it for Windows and Linux - Typhoon 2001.
Hardware requirements aren't too drastic, but you do need a reasonably fast graphics card. I've installed it on the PC I use for video files etc., it's pretty amazing on a 40" screen.
