Fixed bug that causes the game crash. Removed some conflicting elements.
Set in the immediate aftermath of the zombie apocalypse, Left 4 Dead's survival co-op mode lets up to four players blast a path through the swarming zombie hordes and terrifying mutant monsters. Guide your survivors across the rooftops of an abandoned metropolis, through rural ghost towns and pitch-black forests in your quest to escape a devastated Ground Zero crawling with infected enemies.
New technology dubbed the "AI Director" is used to generate a unique gameplay experience every time you play. The Director tailors the frequency and ferocity of the zombie attacks to your performance, putting you in the middle of a fast-paced, but not overwhelming, Hollywood horror movie.
The Source Filmmaker (SFM) is the movie-making tool built and used by the staff at Valve to make movies inside the Source game engine. Because the SFM uses the same assets as the game, anything that exists in the game can be used in the movie, and vice versa. By utilizing the hardware rendering power of a modern gaming PC, the SFM allows storytellers to work in a what-you-see-is-what-you-get environment so they can iterate in the context of what it will feel like for the final audience.
If you're interested in making movies and games in parallel, sign up for an SFM beta key and start shooting your movie on location inside the world of TF2 today.