I am pointy in my ratings, but I can not rate this one badly.
The great= Feels less linear than World At War, you don't need to do one more step before the next action sequence gets evolving (at least, It seems that way, which is good)... the areas are immersive and the USA city level (where the burger king is, and the houses are... the USA flag on the houses... where you need to hide behind those houses....) is really well put out in order to make one feel patriotic. The action pulls you in really well.
The good= A shooter is a shooter, and being creative is hard for developers. This game succeeds in bringing a wide range of levels (ice and snow, mexican style, underwater/ oil refinery type, urban warfare, etc...) and by having what works in the industry (superb shooting controls, level designs are great, and story is fun to follow).
The bad= you may not really know where to go next at times without pausing and checking your objective icon/ map... so not 100% realistic
- The AI is good, but not awesome. (you can hide on corners even if the bad guy saw you and is like 2 feet from you.. he will wait there as long as you play ) So AI patterns could have been more complex... but this is a minor setback...
I did not play at the Multiplayer, but I did in other cod's, and I liked those...
A very solid game.