Rocketball is based on the futuristic sports movie Rollerball, released in 1975. The computer game is similar to Roller Derby in that two teams on roller skates travel counter-clockwise around a banked, circular track. The object of the game is to score points by throwing a softball-sized metal ball into a cone-shaped goal target inset into the wall of the arena. Balls are fired into play, in the same direction players skate, by cannons when play begins and to restart play after the ball rolls out of play or a goal is scored.