UFO: Enemy Unknown

UFO: Enemy Unknown (marketed as X-COM: UFO Defense in North America) is a science fiction strategy video game developed by Mythos Games and MicroProse. It was published by MicroProse in 1994 for the PC DOS and Amiga computers and the Amiga CD32 console, and in 1995 for the PlayStation. Its European PlayStation release is titled X-COM: Enemy Unknown.

Originally planned by Julian Gollop as a sequel to Target Games' 1988 Laser Squad, the game mixes real-time management simulation with turn-based tactics. The player takes the role of commander of X-COM - a clandestine, international paramilitary organization defending Earth from alien invasion. Through the game, the player is tasked with issuing orders to individual X-COM troops in a series of turn-based tactical missions. At strategic scale, the player directs the research and development of new technologies, builds and expands X-COM's bases, manages the organization's finances and personnel, and monitors and responds to UFO activity.

The game received strong reviews and was commercially successful, acquiring a cult following among strategy fans; several publications listed UFO: Enemy Unknown as one of top video games ever made, including IGN ranking it as the best PC game of all time in 2000 and 2007. It was the first and best received entry in the X-COM series, and has directly inspired several similar games, including UFO: Aftermath, UFO: Alien Invasion, UFO: Extraterrestrials and Xenonauts. A remake of the game, XCOM: Enemy Unknown, was created by Firaxis Games and published by 2K Games in 2012.