Zed Heads

Welcome to the realm of G-Lord, a sadistic god with a god complex. He likes to make a single dude with a gun fight hordes and hordes of zombie heads. His victims can only move with WASD for some reason, and their shots are invisible and caused by cosmic clicks. He's not the absolute worst, though! Every time the number of zombies exceeds 300, he kills them all for you! And you can choose how fast they spawn! If you kill all the zombies, he lets you wander the small world that he created for you, and you may choose to end your own life. Sounds from DOOM, Minecraft and freesound.net, and gun from Google search.