The Keep: Zombie Horde

During the zombie apocalypse, the player found an interesting job: taking care of the Citizen Protection Facility, a fortified tower. It has four windows which allow free view into the cardinal directions. During each wave, both a big number of zombies and some survivors move towards the tower. The goal is to protect the survivors from zombie attacks until they reach safety. Between waves, the player can spend the earned money (rewarded for each saved survivor) for new weapons, more ammo or more tower floors. Every other wave is a bonus round during which as many zombies as possible have to be killed with a machine gun: the more deaths, the more survivors appear in the next wave.

In contrast to other wave-based shooters, the waves last relatively long (about five minutes) and even the standard pistol has limited ammo. The alternative is a knife, but it is only useful against zombies which manage to enter the tower and attack the player directly.