With a gattling gun arm what more could you want? Maybe a horde of zombies to mow down? Collect coins and medkits as you upgrade your parts and abilities and clear out the zombies and monsters wandering through the abandoned subway system. Clear the way for the doctor and fill every horrible monster you see full of bulletholes!
Use the mouse to aim and shoot. Use A and D to strafe back and forth. Use the SPACEBAR to bash your enemies.