Zombie Destroyer: Facility escape

To save the world from the zombies, you must activate all the bombs and escape from this facility, before they escape...Earn money killing zombies and activating bombs to buy new weapons.Each bomb armed the dificulty rise till you die or save the world ;-).
*WSAD* = Move the Hero.*space* = Jump.*Mouse* = Shoot and Defend.*Shift* = Run.*F* = Buy guns.*B* = Earn money.*scroll* = change guns.*c* = Third Person.*Ctrl* = crouch.