Space Intruders

Space Intruders is a clone of the arcade game Space Invaders where you move a craft, left or right on the bottom of the screen blasting a formation of aliens above. The aliens above just move left and right dropping bombs and don't descend down the screen. In between yourself and the aliens are four shields which lose parts every time you or the aliens hit one. If you are hit by an alien's bomb then you lose one of three lives.