In this game you have a cannon that is used to shoot the approaching enemy units defend your base. You can also release your own units that will fight the enemy units if they meet them and attack the enemy base if there are no more units to fight. Use A-D or the left and right arrows to move your view. Use W-S or the up and down arrows to change your cannon's angle. Press Space to fire. You can fire the cannon without touching the keyboard. There are buttons for this in the GUI. To train attacking droids click on their icons in the bottom.