Left 4 Dead 2 is a co-op first person shooter from Valve. In the game, 4 Survivors try to make it through multiple campaigns with different game modes by using a variety of weapons.
Pro Not much different from its predecessor
While the game has been improved from the original, if you did not have much fun with Left 4 Dead, you will probably not get much enjoyment out of the sequel. It is essentially the same game and some have complained that it just feels like a large DLC update.
Pro Unique and diverse co-op versus mode
Left 4 Dead 2 features a versus mode that pits two teams against one another. For the survivor team, it is basically the same game as the normal campaign. However, versus mode adds a new way for teammates on the opposing team to work together by playing as the infected, which opens up a whole new play style and set of strategies.
Pro Invigorating team-work dynamic
Left 4 Dead 2 requires players on the same team to cooperate in order to survive. This makes for an interesting team dynamic, as it will be increasingly difficult to make it through a level if any one player on the team decides to go off on their own instead of staying with the group and cooperating.