Heart of the Alien happened in 1994.
Heart of the Alien was created in 1994.
Alien Crush happened in 1988.
Alien Carnage happened in 1993.
Heiankyo Alien happened in 1980.
Alien Breed happened in 1991.
Alien's Return happened in 1983.
Alien Hominid happened in 360.
Alien Soldier happened in 1995.
Alien Cabal happened in 1997.
Alien Shooter happened in 2003.
Alien Legacy happened in 1994.
Alien Highway happened in 1986.