Instructions and controls: Choose the difficulty you want: EASY, MEDIUM, or, HARD. You must then click an unlocked area on the map to play. Move your tank using the left and right arrow keys. Adjust your cannon using the up and down arrow keys. Shoot at your enemies by pressing the space bar or M key. Use the Z, N, or 1 key to release missile. Hit the R key to reload. Collect all the lightning bubbles which you can use to purchase upgrades after each level.