In 1985, Durell Software released "Saboteur", a game in which the player controls a ninja who has to infiltrate a facility and find a disk while avoiding or defeating security cameras, guards, and dogs. "Retro Gamer" has called this "the original stealth game". Mindscape's "Infiltrator", released in 1986, combined a flight simulator with a stealth-based "ground mission". In this ground mission, the protagonist attempts to sneak into enemy territory using false IDs to avoid detection and knock-out gas to incapacitate enemies. The goal of this mission is to photograph secret documents while avoiding alarms.