The world has gone to hell, and the zombies are taking over.  In this game you play both human and zombie.

You can only change from human to zombie and back again 5 times.

Mission or survival modes.  Mission objective points shown on the map.  

If you are changed from your primary form during a mission, you have a free play (go nuts) period until you change back and continue on your mission. 

Avoid drain covers, you fall in them and lose hitpoints.

You can only kill the zombie dog with a mine.

Watch out for crazy robots.