Ceiling Zero

Ceiling Zero is a fixed screen shoot 'em up. It features an alien mothership that is protected by the titular ceiling, a power field that the player can't shoot through. The mothership throws various objects onto the screen that will bounce around until the player has shot them all down, or he is killed when colliding with them. Once all the objects have been destroyed, the ceiling moves down one step and another wave is released. The player's goal is to survive until the ceiling has reached the floor. There are three different kinds of objects, and they differ, not only in appearance, but in their speed and how they move. In addition to these, there is also occasionally a creature that attempts to land. If it succeeds before the player shoots it down, a life is lost, no matter how far from the player it is. Similar to other early shooters, the player is restricted to move left and right.