Eliminate hordes of nasty aliens that have infested the local streets and buildings. Move your cross hairs around the screen and shoot just about anything that moves. Roll out of the way to avoid alien attacks.
A homicidal alien race is invading Earth, and the only thing that stands between them and world domination are a special forces team known as the "Alien Busters". Three playable characters (a man, a woman, and a novelty character) and pick-up or power-up special attacks. The player (one player only on the Master System version, up to two players on the Mega Drive version, three on the arcade version) selects from the three different characters to embark upon a quest to save the Earth from an alien invasion.