You are on a routine patrol mission in an unknown section of the galaxy when you are suddenly fired upon by alien attackers. Armed with ship's phasers and an uncanny ability to pilot your craft, you must return fire, dodge the aliens and avoid incoming missiles. Your weapon fires vertically and you can maneuver your ship only around the bottom half of the playfield.

There are 11 different types of aliens; they attack in waves of six. After you progress beyond the 11 levels of play, the action repeats itself until you have lost all your ships. You gain a new ship (up to three bonus ships in all) for every 20,000 points you score. The faster you destroy all six aliens in a wave, the more points you will score.

Three skill levels are available. You must also decide whether you want the enemies' missiles to be regular or guided. Regular missiles fly straight while guided missiles home in on your ship. The game ends only when you have lost all your ships. ~ Brett Alan Weiss, All Game Guide