Your aim is to obliterate all the enemy ships on the scanner and then dock with your mothership, without running out of fuel. Use your scanner to locate enemy ships. They appear as blue or yellow dots. Your mothership is indicated by a green dot. Fireballs appear as red dots until they either hit you or burn out. The bottom right hand corner of your cockpit is equipped with a movement scanner. Once an enemy ship gets within range, it starts to generate fireballs which if avoided eventually burn out. If they do hit you, your fuel is lost. When your fuel starts to run low, a warning siren can be heard. When each level has been successfully completed, you are given a rating. The game is over if you run out of fuel or if your mothership sustains four hits. Fuel is renewed at the start of every level.