Alien Brigade: 1990
Developer: Atari
Genre: Shooter
Alien Brigade Game Manual

The Plutoid Alien Zombie force has infiltrated the Army. They look like soldiers but are actually Aliens from outer space.

You control a special task force to destroy the Aliens. As you shoot away at nasty enemies, you can earn powerful weapons, rescue hostages and most of all, stay alive. The challenge is there–beat the Aliens or you’ll have to join them.