Left 4 Dead 2 is a 2-4 player co-op first person shooter that requires tons of cooperation and intense zombie slaughtering in order to survive. There is a variety of enemies, weapons, and objectives to keep things interesting, with co-op that is focused around having fun playing with your friends.
Pro Turn the gameplay upside down by hunting the hunters in a unique co-op mode where you play as the zombies
Left 4 Dead 2 features a co-op versus mode that pits two teams against one another. One takes on the role of survivors, which is very similar to the normal campaign. The other team, however, plays as the infected, opening up a whole new play style and set of strategies.
Pro Invigorating cooperation based survival dynamic
Left 4 Dead 2 requires players on the same team to cooperate to survive. This makes for an interesting dynamic for teammates, as it will be increasingly difficult to make it through a level if any one player decides to go off on their own.
Con More of the same
While the game has been improved compared to the original, there are no wildly different game mechanics. If you did not have much fun with Left 4 Dead, you will probably not get much enjoyment out of the sequel. Some have gone so far as to complain that it feels like a large DLC update rather than a discrete game.