Some good points, some bad, and a current opinion.
Okay, the snow level was actually quite impressive but perhaps just a gimmick. Moving onto the airport... uh... you must have heard about this controversial (i.e. clever marketing) scene by now. It
is disturbing. I think it's a good inclusion for a game as it will provide more evidence for or against the influence of games on kids that shouldn't be playing a 18 certificate game anyway which should lead to the fining or incarceration of their useless parents.
Then off to Brazil, that's always fun. So many weapons! Double desert eagles and three+ kinds of shotgun!
Then to... the diner, and I get my hands on the thermal sniper rifle. Happy Bunny! I then notice why the games pace is so fast and why I'm getting killed so often. I can understand how in real war time is the key and when you're commanded to "go go go!" it's pretty vital for the collective effort, but as everytime I stuck my head out of a doorway it was getting blown off, I decided to ignore commands and pleas to rush and just take my time and pick off the enemies. When I discovered there was a refill for the sniper rifle, the level was cleared of enemies before I decided to leave (every 30 seconds my commander was screaming at me

)
I have to say I'm enjoying the single player a lot more now. The usual military storyline with an interesting "guess" at the next conflict/world war scenario! The plot is fast paced with early twists, double takes and turns. There's a lot of polish in this game, a lot of sweat went into it and it shows.
Now what I don't like:
It is certainly difficult/realistic. You can't just run around and shoot everything, even if you have regenerative health. This has annoyed one of my friends who can't repeat the same tactics he used in UC2. I have patience/ am lazy, so I adapted. However the realism of guys appearing on rooftops behind you after you shot a few of their friends is quite annoying. Who shot me? Where? Where can I run for cover? Oh yes, there is no "cover" button. I am baffled at this. I am also annoyed at FPS games in general for not being able to let me walk backwards through a door. Good lord I can't see shit. Let me float up these ladders.
The auto aim is only good for stationary targets but good lord it's turning me into a robot that is too lazy to aim and when faced with a running target, can't shoot for shit. Uh I should turn it off, but me so lazy. I like it, and that's bad. The recoil and handling of guns is otherwise fine/satisfying.
Shooting friendly soldiers. Who asked them to have the same shape as enemy soldiers? Who asked them to get in my way when I'm taking a shot? Jesus I cannot blame friendly fire in real life war. You see a guy with a gun running towards you, what else are you supposed to do?
The frantic pace of war. This shit is intense! I recall KillZone 2 and Lost Planet 2 trying to implement some of the old Saving Private Ryan / Starship Trooper atmosphere. They didn't quite hit the mark as I believe you just don't buy into the fantasy. MW2 is a modern setting with modern technology and guns, and it's fucking scary. Bullets flying bloody everywhere! Constant waves of enemies! Nowhere to hide! I hate that blood in your eyes shit too. Fucking can't see shit! This all makes for a panicy, frantic and sometimes frustrating game. If you can't keep your calm and do things by the book, under pressure, don't play this game, you're wasting your money. As for me, I'll happily sit in the tower with my sniper rifle till the cows come home. Sorry darling, my mobile was on silent...
Online: jumping on the current trend of "oh fuck we didn't really test online properly" MW2 has had 2 patches so far and fuck all online play. Some dodgy and boring workarounds exist, but that's just lonnnnnggg. Have yet to test co-op, but if it's anything like single player, your friends who like arcade games will not like this.
Currently I think the game is great, but not everyone's cup of tea. If you like fun arcade playful games, this is NOT one of them. It's tough, it's brutal, it's got fucking lots of guns in it that kill people and you, A LOT. I'm still not even sure I like it, but I'm enjoying some bits. I'm quite shocked to see Scottish and English soldiers as part of an elite squad in an American game but that's nice! The game also features some gimmicks which make me think they were wasted as one off scenes but at least you can replay every level. I bought this cheap as part of a supermarket price war, and looking over the COD series, the prices have remained quite high, so er.... if you see it cheap, I'd buy it and then sell it again when the price goes back up!