[userbinator]

Tetris seems to be one of those games that people love to size-optimise in Asm; here's a few in the <512b category:

http://www.pouet.net/prod.php?which=33942

http://www.pouet.net/prod.php?which=6951

There was a competition too, based on a standard appearance and behaviour, and the winner is 363 bytes:

https://files.scene.org/view/mags/hugi/compos/hc22fin.zip

Vaguely related; chess game in 487 bytes:

https://news.ycombinator.com/item?id=8954630