The player loses a laser cannon each time it is hit by a falling meteor, a guided missile, a non-guided salvo, or by shrapnel from a nearby explosion, and any time a spinner reaches the ground, even if it does not strike the gun. Each target hit increases the player's score; it decreases by half as much each time a meteor reaches the ground, or a laser cannon is destroyed. An extra gun is awarded each time the player's peak score increases by 1,000 points.