Too little innovation, too many scripted sequences and the overall rambo style bring down this enjoyable shooter...
Graphics 9/10
Graphics are up-to-date, outdoor areas especially forests look refreshing, water (in the few levels where there is water) looks really detailed, caves in Vietnam are adequately misty, etc., but the best part are definitely the detailed characters, especially their faces. There are many close-ups during dialogues and cutscenes so that you can enjoy the work that went into the modeling and textures of main characters.
Sound 7/10
More or less the same as before. There is little which can be done about the sounds in shooters anyway. Music is not catchy, sound effects have a high quality but are the current standard. I saw some innovations, for example during the level in caves below Vietnam, the music played ominous tones as enemies with knives attacked you from various directions. Yet this has all been here and it has been improved only minimally. Another thing, which I think made the sounds average are the voices, they are not bad or anything, but they aren't epic either and don't even get me started on the russians, they all sound like russian Hollywood cliches.
Story 6/10
Some might argue that is was the most innovative story among latest CODs, or at least the way it was put to you, but really the game is a shooter and the story reflects it, in other words it is simply poor.
Most of the game your character will sit in a chair during an interrogation by some unknown persons and recalls memories of what has happened. This cuts away many tensions as you know your character did survive everything if he is here to recall it, so many scenes during the game where you are on the brink of dying are just funny instead of being all-action, because you already known how they will play out. Of course some might argue that in all games you survive, but the fact is, you cannot know that for sure, while here you do. And while other games might have plot twists because of it, Black ops is missing any of these twists. The only twist here you will see coming from at least half-a-mile afar.
Second thing is, once your character gets off the chair, the game, instead of trying to be epic towards the end, starts something which is about on the same level as a regular mission. That, and you also get to know your interrogators, which are in fact your friends, so the treatment they gave you is totally not understandable.
Gameplay 7/10
Where should I begin? The positive thing is that gameplay is more or less the same as the previous installments, so plenty of shooting, quick action, nice team to help you, etc. Almost all negatives are common to all the new CODs, but while in the previous games you could tolerate at least some of them because the games were still pretty revolutionary, this game is just the same as those before, it doesn't even break new ground like Bad company 2 did with the wall demolition. So the negatives I see are:
Too many scripted sequences - these might be fun the first time you see them, but they get old fast
Sometimes really stupid scripted sequences - like dodging a flaming falling aeroplane in a jeep, really, the heroes of Black ops should have been dead many many times over, if it wasn't for the goddamn luck everytime, everytime
Appearing enemies - a lot of enemies are set to spawn at an exact place at an exact time out of nowhere without any variations at all, so you can be camping half-an-hour behind a barrel and the hallway before you can be empty but once you make 3 steps forward (not 2, three) 2 enemies will charge from the passage right, so this game is (at least at higher difficulties) a lot of trail and error and after a time you can play it almost blindfolded
Basic soldier dying - for example, your team mans a boat, there are 5 people, 4 are of your team and one is a private you've met on the way, guess who is the one who is definitely going to die (and these things happen more times than I could count and towards the end feel really awfully stupid, like watching a cheap hollywood flick or old Star-treks where redshirts die in hordes but the main heroes are simply untouchable)
Rambo syndrome - 2 people against 50 usually, without any stealth or special equipment like claymores, or 1 chopper against 10 sam turrets and 3 choppers, no problem, how the hell do these machines you man survive 30 rockets anyway? This would be fine if this game at least presented itself as a Rambo clone from the start, but it doesn't, instead it tries to present itself as a team and war game and such rambo-like behaviour as in the second half is not acceptable...
Undetectable stealth - there is a rule here, you team characters will not be detected unless they want to be, the funniest moment was when your team was trying to avoid a dog patrol and they crouched on the ground (without any cover) and the dog looked their way, then simply started running in almost the opposite direction, at that precise moment I thought, what the hell?!
Endless soldiers - at some places enemy soldiers will spawn indefinitely until you do something you should, this is just...stupid...
Either way the gameplay is fine, IF you haven't played more than 2 previous installments, if you have it feels old and boring, unless you are a real true hardcore fan of shooters. Making the same thing twice, like it was with Baldurs gate 1 and 2 or Fallout 3 and New vegas, can usually lead to a great second installment, but making the same thing over and over again, the fourth or even more times, just leads down the Need for speed way of pumping out the same game every year for obviously only profit.
Replayability 6/10
Game is hardly replay able because of the loads of scripted sequences that just get real old (even almost all the knife kills you make are scripted to look always a certain way) fast. The only reason to replay it, is to gather intel, which on the other hand is done nicely, in the form of top secret documents which get unlocked everytime you gather another intel box. The minigame of Zombies is entertaining, but soloing it is pretty hard. Also, I encountered crashing without any error during the game, after which I had to replay the entire level, this was also a letdown since I never had problems with previous COD installments.
All in all, this game is more of the same as the previous ones. I would recommend trying it if you have not played more than 2 of the previous ones, or if you have and still think you can enjoy another one. You will see for yourself if the mechanic got too old for you, like it did for me, or if you are still satisfied with it.