The title screen from Space Strike.
Space Strike is a 1982 computer game for the IBM PC family of computers, created by Michael Abrash and published by Datamost. Space Strike is essentially a clone of the popular Space Invaders video game of the late 1970s.
In both games, the player controls a small mobile firing platform that he moves side to side along the bottom of the screen. Waves of aliens attack from above, sweeping back and forth and slowly descending. Barriers provide cover for the player, but are degraded by weapons fire both from above and from below. The level is complete when all the aliens are destroyed, but ends if the player gets shot or if the aliens descend to the point that they collide with the player.