Use Machine guns, missiles, bunker gunners and all sorts of weapons to defend your base from helicopters, Bomber planes, ground soldiers and even aliens plus much more. You have a choice of 3 difficulties and you can upgrade your weaponry with the money collected from kills. You must also protect your buildings because they can be turned into gunners and one of them is your shop and source of ammunition but even if you loose your shop, sometimes you will get a care package with a random prize or nothing if the enemy got to it first.