The Left 4 Dead games were great cooperative fun. For the uninitiated, four players blasted their way through frantic zombie hordes in the L4D games, working together as a team just trying to survive. Developer Turtle Rock Studios, which was acquired by Valve prior to the release of the first game, re-established itself as an independent studio…

Source: Hot Hardware – Back 4 Blood Performance Review: A Worthy Successor To L4D