"Zombie Army Trilogy" is an extension of "Sniper Elite 2" out there more than a year on PC only. This game combines 3 campaigns composed of several chapters in which the sole purpose is to vent by killing the undead or skeletons. Said like this you would think that we are in the presence of a basic GST & it's real party ... but only solo. In multi / cooperation game takes on another dimension, especially 4. The atmosphere coupled with horrific scenes of horror films of the 80s (music reminiscent of John Carpenter themes) give a unique character to the game & do some forget the limits of the game and the little innovations proposed ("Gears of War 3 "best offered in 2011 with a more muscular action). The "kill cam" so Max Payne is also fun although it adds nothing to the game.
In short this "Zombie Army Trilogy" is to buy if you plan to play multiplayer online as solo action gets a little monotonous after a while. It is also regrettable that the programmers did not foresee a 2-player mode on the same screen (split screen).