When a new wave starts, at the top of the screen will note which wave that you are on. The only control that you need to know for this version is click to shoot really. In total there are 8 waves and 1 zombie apocalypse. The apocalypse is the hardest wave of zombies that there is. It is possible on this level that a speedy zombie can reach your castle in just 0.5 SECONDS! (Not a glitch!)