(adsbygoogle = window.adsbygoogle || []).push({}); Leave the gate from the mainframe to teleport "A" closed. Open up everything from entering through the garage area. Leave the door shut from the outside area with the m1 carbine to the animal research area. One guy covers the window at the rear of the m1 area (the area overlooked from teleport "A" window) and the others shoot zombies coming down a straight line from the rear of the map.

If you cant get to the mid twenties every time without breaking a sweat doing this hang up your controller.