Starving monsters resembling mutant turtles join with spiders invade your territory. However, they will meet a warm welcome - several types anti-turtle towers. Freestyle gameplay allows the structure to be placed anywhere in the open field. But enemies' forays also go on a variety of trajectories. If 20 of them reach the gate the battle is lost. Gun and moderator cannot shoot ghosts or flying enemies. Rocket launcher shoots only at those flying. Electrical tower can spot all enemies. At the first level there are 21 per wave, the second 28, third 35 and the fourth is 50. Each seventh wave features the boss.