Oystron

Oystron is an action game developed for the Atari 2600 by Piero Cavina and released in 1997. It is one of the earliest hobbyist-written games for the console. The game, Cavina's first, was initially made available as a freeware 4 KB binary file designed for use on the Starpath Supercharger and with Atari 2600 emulators. It was later released in cartridge form by XYPE, a group of Atari 2600 homebrew developers.