[Ada95] Gravitationally Challenged Blocks
Year: 2001
Ahem. Ssh! Don't say "Tetris", it's copyright! The Ada95 version of this program remains unfinished for one reason: I started it about 1 month too early, before being introduced to abstract data types. Hence it's made of extremely nasty code.
It has since been reincarnated in a much, much better format.