It's easily the best game for the Xbox 360 launch, even if the graphics is not all optimal but it's an awesome game!
When you start up the campaign you'll play as an Russian Soldier, and you'll go through some very basic training and pretty soon after that you're into combat with the Germans within the boarders of Russia.
The game plays VERY smoothly with an excellent rock-solid really high frame-rate that doesn't slow down becuase it's alot happening on the screen, it stays constantly the same frame-rate. Even if the graphics might not be the best around the launch line-up but it has graphics that obviously just works, you will not think about it becuase everything looks natural in a good way without all those effects you'll see in games as Perfect Dark Zero such mad details like moist walls and see the water drip from the walls and all that, but that's not needed in Call of Duty 2 becuse everything is balanced very well with sounds and invoiment so it doesn't need anything more to make you belive that you're on the battlefield.
The sounds is terrific even if some sounds could have been a little like the previous games, then I'm thinking most of the Thompson which in CoD2 has a little too Movie-like sound, something taken right out of an action movie or something. But still, all sounds works terrific and the voice-acting is great too and it's an whole bunch of it basicly all the time. But the bad thing about the voices is that the Germans are the only ones that doesn't speak english, just to make them feel unhuman compared to everyone else in the game (Hehe, just becuase you're not speaking english doesn't mean you're less a human, but it feels like the game is pretty much built up like that)
Also the A.I is good too but they're probably better performed by your allies rather than on the enemy, they will react on many different things and they will hide behind crates and objects but it's usually very predicteble where they are and what they will do, like when they will show up their head and try to shoot you and then you're right there with an Lee-Enfield and just shoot'em but... If you think like that I recommend the harder modes of the game.
Even if the single-player campaign is a little basic with all the objectives as you'd except, Kill them, destroy that, repair that, but just becuase of the AI, the envoiments and the excellent voices you'll play it through just to... finish it basicly and have fun becuase it's a lot of it, like when you start the training and one of your comrades asks the Sargent why they're not having real grenades instead of... Potatoes they're throwing around in practive purposes.
The Single-player in Call of Duty 2 is the best WW2 experience possible, and also the Multiplayer is real fun even if you're only playing splitscreen becuase the frame-rate is solid also there (but obviously slower than in regular screen-modes) and it runs smooth enough even there to get a whole lot of fun with many maps you've seen in previous games and many new from the new single-player game. Yet, I haven't tried it on Xbox live so I can't say anything about it but... if it works as awesome as Perfect Dark Zero online, then you have it all there... Awesome singleplayer, great LAN multiplayer and probably just as great Xbox Live functionaliy and experience.