What we learned from Left4Dead

Set during the aftermath of an apocalyptic pandemic, the game pits its four protagonists—dubbed the "Survivors"—against hordes of the infected. There are four game modes: a single-player mode in which allied characters are controlled by AI; a four-player, co-op campaign mode; an eight-player online versus mode; and a four-player survival mode. In all modes, an artificial intelligence (AI), dubbed the "Director", controls level pacing and item placements, in an attempt to create a dynamic experience and increase replay value.

Enjoy tonight!