Defend yourself with your superior computer coordination! Each enemy has a letter printed on it. To kill them, hover your mouse cursor over the enemy and press the letter (or number or symbol) on your keyboard.
Also, when HP is low, two-letter healthpacks and bombs may appear. Healthpacks heal 20 HP, bombs kill all enemies on the screen. You must be hovering over the item while pressing both letters in a row to get these.
Spacebar to pause, although .swf file name says ‘beta’, it’s not, it’s a completed game