Left 4 Dead "Exterminators"

Do you like circling around the city on the chopper and eradicating the horde of zombies out of Gantling? Then, that is for you.
One of the most unusual maps for survival.

Note: SP - singleplayer with AI (corrected AI)
          MP - multiplayer with friends (not corrected AI)

P.S. The Gantling trembles during shooting - that's the engine's bug.