Joust is a popular arcade game developed by Williams Electronics and released in 1982. It was one of the first and most successful two-player cooperative games. The players control two knights riding a flying ostrich and a stork and will have to defeat all the enemies, one level after another.
Joust was ported to many platforms, including NES, Atari 2600, 5200, 7800, Apple II, Macintosh, and many others. GamesNostalgia offers you the Atari ST version, released in 1986.