Zombie Mall Defense

Zombie Mall Defense is a game in which you defend your malls from ever-bigger zombie hoard waves. Expand the map, discover new turrets, find new zombie types, and come up with the best strategy. The zombies build houses, which can make more zombies, and the houses can specialize in to advanced zombies. You can see how this might get a little out of hand... The whole game is 3MB and made by one guy in his free time, and the code is so highly CPU optimized that 100,000 zombies and 20,000 turrets can be on the battlefield at once and it still runs smooth. It's been playtested hundreds of hours by 4 different people, and all of them got addicted...