They are comming from space. They are ugly, sinister and evil-minded creeps. You must survives 55 waves of creeps attack by placing various towers on the 3 maps. You will lose life everytime an enemy unit gets through the map. You can upgrade your defenses as you like. There are three difficulty levels and eight unique towers to choose from. Protect our planet from the creeps.
Build more towers to destroy wave after wave of creeps, or upgrade your existing towers for more stopping power and more points.