X-COM: Alliance is a cancelled video game in the X-COM series. The game was developed by two different teams of MicroProse developers between 1995 and 2002. It had the player assume the role of commander of the militarized scientific mission lost in space during the aftermath of X-COM: Terror from the Deep.

X-COM: Terror from the Deep is a strategy video game developed and published by MicroProse for the PC in 1995 and for the PlayStation in 1996. It is a sequel to X-COM: UFO Defense and the second game of the X-COM series, this time taking the war against a renewed alien invasion into the Earth's oceans.