The game is notable, among other things, for the adjustable armored jaws of the player's spacecraft. Opening the invincible jaws of the ship increases the spread of the player's shots but exposes the vulnerable cockpit. Obtaining one weapon upgrade allows the ship's jaws to be set half-way open (a 3-shot spread) or closed (with increased damage), and a second upgrade allows them to be closed, half open, or fully open (a 5 shot spread).