Try to escape a city that is infested with flesh eating zombies. Find new weapons, upgrade them and kill hundreds of zombies in 10 levels and 3 challenge levels.
It's a nightmare. You are trapped in an abandoned mine with an injured comrade at your side against God-knows-what. Make your stand, get out alive. Three words of advice: shoot to kill. These things are not human, they are monsters..
Zombies have attacked and mankind has been devastated. Every day is a battle in the war to survive. Few remain to hold them off. Shoot those zombies and save the world.