Left 4 Dead 2 is a cooperative first-person shooter game. It is the sequel to Valve Corporation’s award-winning Left 4 Dead.
Like the original, Left 4 Dead 2 is set during the aftermath of an apocalyptic pandemic, and focuses on four survivors fighting against hordes of the infected. The survivors must fight their way through levels, interspersed with safe houses that act as checkpoints, with the goal of reaching a rescue vehicle at the campaign’s finale. The gameplay is procedurally altered by an artificial intelligence engine dubbed the “Director” that monitors the players’ performance and adjust the scenario to provide a dynamic challenge. Several new features have been introduced: new types of infected, melee weapons, and a story-arc that connects the game’s five campaigns together.
Not the most demanding game on test, but the Source engine is used in many games still played today.