Extra modes for more fun:
-Zombie Mode - limited time to finish each level, unlimited ammo to kill zombies xD.
-Zombie Mode No Timer - the same as Zombie Mode but without time limits.
Changed gameplay mechanics:
-Now you can shoot a gun!
-When guards see you they attack you it's not instantly game over.
-Controls changed to incorporate shooting a gun.
-To use an object you need to aim at it.