An alien invasion is taking place somewhere in the world, your mission is to protect the cities from a nuke destruction, but that’s not all, they will try to destroy you with all their ships so move fast with the cannon and don’t allow them to win, but be aware that if you resist the invasion they will send you faster and advanced ships.Tilting your Android device to the left or right you can control the direction of the cannon. If you feel that you can’t handle the situation you can always use one of the bombs by touching the cannon with your finger, but remember that you can only use three bombs and that the missiles are immune to them.