The space ship Steel is so advanced that it is completely operated by robots. As usually in video games, these robots went havoc and have to be put out of business. This job falls to the player who goes on the ship to shut down the security system. He is disguised as robot, but this does not stop the other ones from attacking.
So the player wanders around the maze-like ship, consisting of non-scrolling screens, with the ultimate goal to collect eight cartridges. The player can hold up to three at the same time and needs to bring them to the main control panel. The enemy robots can be blasted away with the laser weapon, but contact costs energy. Losing all energy results in death, but it can be refilled in special stations which are spread over the ship. Using them costs points from the high score. There are also some terminals which need to be cleared by solving a mini game. It basically consists of shooting a wall enough within a time limit without being hit by bullets.