Left 4 Dead is a cooperative first-person shooter video game. It was developed by Turtle Rock Studios, which was purchased by Valve Corporation during development. 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 spawns, in an attempt to create a dynamic experience and increase replay value.
Left4Dead uses Valve’s proprietary Source engine and as expected it is a smooth, almost bug free experience on modern day hardware. The 4890 as expected handles this engine with ease driving solid and consistant frame rates over the 50fps for the most part – a flawless result.