Janitor Joe is a DOS game by Kevin Bales in which the player must gather keys and escape from a NASA station. Bales released the free game as a teenager via BBSs in Atlanta, and later said, "I only spent five days on the programming part. I didn't write it to sell — I was only experimenting." Nonetheless, the game was widely distributed and played. Bales also wrote Castle Adventure.
The primary dangers are falls, mad robots, and a limited supply of oxygen. Each level features a different type of device to aid Joe in escaping: