An alien invasion force has colonized planet earth. Now it is up to you to infiltrate their strongholds and completely eradicate the alien threat. Your mission: Kill everything in sight! Survive the onslaught and make your way through these bizarre fortresses, one stage at a time. Take no prisoners.

An alien invasion force has colonized planet earth. Now it is up to you to infiltrate their strongholds and completely eradicate the alien threat. Your mission: Kill everything in sight! Survive the onslaught and make your way through these bizarre fortresses, one stage at a time. Take no prisoners.