Pirates took possession over a part of space and founded eight colonies. The player's mission as Earth's delegate is to destroy them in this vertically scrolling shooter.
Each level has to be crossed twice, the first time the goal is to destroy the reactor at the end of the level. Then the colony falls into darkness and the player tries to destroy as many buildings as possible during a second run. Some structures are marked, those give extra points or in some cases an extra life. Those are needed because the pirates are not in the mood to give in without a fight, contact with an enemy ship or missile means instant death.