C-40 Contest
From IFWiki
The C-40 contest is a minicomp being run by Sam Trenholme to create a compelling Z-machine game that fits in 40960 bytes or less. Any kind of game created with any kind of system is allowed, as long as the resulting code is a v3 or v5 Z-machine file that fits in 40k.
The contest was announced on rec.arts.int-fiction on October 3, 2007.