TetrOS

Another tiny rewrite of Tetris: like the older BooTris, it squeezes the entire game into the cramped space of a boot sector, by trimming it down to half a kilobyte. The PC then boots directly into the popular tile manipulation game, which runs OS-less (and without taking up visible filesystem space).

This version manages rudimentary VGA graphics despite its compact size. Granted, some compromises are made - no speed-ups or level advances, no "next piece" indicator, and the blocks (not lines) are counted in hex. The basic idea still stands: move, rotate or drop the random 4-block shapes as they fall, form complete horizontal lines to clear them, and try to prevent the pile from reaching the top of the well. The well is 12 blocks wide, instead of the standard 10.