You are given a certain number of cores per level. Load them into a cannon and shoot down various objects. The level is considered completed if all the dominoes are knocked down.
Gun turns - hold down the left mouse button and move the pointer left and right on the screen. On a mobile device, move your finger left and right on the screen. Shoot - Press and hold the button at the bottom right of the screen. The power of the shot will increase - a numeric value will appear to the left of the button. Release the button at the right moment and a shot will be fired.