The player controls a spaceship battling alien spacecraft. Like other early similar arcade games, it is controlled by four buttons: rotate left, rotate right, thrust and fire. The game was particularly unique in that the player could choose different upgrades for the first three levels. One upgrade would allow the player to shoot in a three-way pattern, another would allow the player to fire forward and backwards, and the third would allow all the firepower to be concentrated in the front.
At the conclusion of the following round, the player would then pick up another shell, although multiple ones could not be used together. The different firing patterns made each round seem slightly different. Between rounds and during the attract mode, the alien commander would taunt the player through the use of synthesized speech. The game continues indefinitely but stops calculating the score after the completion of level four.
At the beginning of each level a synthesized excerpt from Aaron Copland's Fanfare for the Common Man is heard.