Alien invasion or space invasion is a common feature in science fiction stories and film, in which extraterrestrial lifeforms invade the Earth to exterminate and supplant human life, enslave it, harvest people for food, steal the planet's resources, or destroy the planet altogether. It can be considered as a science-fiction subgenre of the invasion literature, expanded by H. G. Wells's seminal alien invasion novel The War of the Worlds, and is a type of "first contact" science fiction.

Phantasy Star II is a science fantasy role-playing video game developed and published by Sega for the Sega Genesis. It was released in Japan in 1989, North America in 1990, and in Europe in 1990. It was later ported to a variety of different platforms. An updated remake, Phantasy Star Generation 2, was released for the PlayStation 2 in 2005 in Japan.