Your city is under attack by commando raiders, and it's your job to defend it! You control a large gun at the bottom of the screen. Choppers will be flying in paratroopers, both of which need to be destroyed. If a paratrooper makes it past your fire and lands, it will damage and eventually destroy one of the buildings in the city. After a building is destroyed, the paratroopers will then begin tunneling towards your gun in an effort to destroy it. Occasionally an airplane will fly by and drop a large bomb. The bomb needs to be shot before it lands, or it can destroy the entire city! The game ends when your gun is destroyed by a bomb or a paratrooper.