Shoot and exterminate aliens in this 3D first person shooter! Alien Slayer 3D is a cool 3D First Person Shooter (FPS) playable online. You have to accomplish various missions and you need to destroy the alien infestatino. Alien Slayer 3D - Get rid of the alien scum. Military must test your skills before they send you to some serious missions. Eradicate the alien infestation and complete the mission objective.