Super single-player fun, multiplayer rather moderate ...

Single Player, as well as co-op (split screen and online):
GREAT! Of course, here and there over the top to the predecessor COD4: to beat Modern Warfare 2, but to play nice: Modern Warfare and COD! The campaign is what Call of Duty is just so very linear and very varied, also short. Nevertheless, I must say it was quite exciting, I have about 3 sessions needed to play through it on the second level of difficulty of four, so rough 6 hours but had 0 console experience. Once again, I would not necessarily play as the but would be too boring if you know the story already history.
Now the best part: The Co-Op or Special Ops where you have to complete missions together either with a friend / a friend or just fending off the normal multiplayer maps waves of enemies. This prepares a crazy fun, the motivation to create more waves is gigantic and the missions are demanding, but really schaffbar. All in all, still succeeded!

Multiplayer, online and offline:
The online multiplayer is really sad frustrating if you are not a high-flyer on console, because so many weapons are too strong or almost unfair unbalanced, and just play most opponents mad cowardly or bad. If Only sitting around in corners, are only used mortars, etc., then any gameplay goes to Modern Warfare 3 immediately down the drain 'Therefore, I play only single player, and am happy with it;)
The offline multiplayer for up to 4 players on one screen is just like any other, there are several game modes and several teams, nothing special, but nothing bad either '

Overall I have to say me the game compared to Modern Warfare 2, what I really thought that was really good, and compared to Modern Warfare 1, which in my opinion the best multiplayer shooter anyway, really disappointed because it is too unbalanced, too unimaginative and since I do not one before, for some new maps and game modes to spend even more money 'Since Call of Duty is but primarily known for the multiplayer, I found it quite disappointing, do not play it and it is here now in the closet' Well, not such a bad review but because the single player is fun really.