Infestation

You are trapped in a zombie survival simulation. Alone you are to explore the vast world of infestation, killing or running from the zombies chasing you. The only way to leave the simulation is to fight the Zombie King. In order to fight the zombie king though, you will need to roam around the simulation and find the 3 zombie mutant gravestones and kill them for their artifacts. With these artifacts, you can finally face the King, good luck.