You control a cannon and must destroy all enemy ships. They will also return fire, so stock up on armor that appears in the sea in time.
On the computer: Control the cannon - press the left mouse button (the pointer should be in the game window) and move the mouse left and right. The power of the shot is adjusted by a slider at the top of the screen. Shooting is a button on the screen. On a mobile device: Gun control - touch the screen with your finger and move left and right. The power of the shot is adjusted by a slider at the top of the screen. Shooting is a button on the screen.