Great story, if short, overly difficult multiplayer for casual gamers.
The story is great. Every level is engaging, and while the story is short, it's not short on action and fun moments (snowmobiles, lots of stealth, gun battles raging, etc.). There are a few moments that make you say WOW! and it keeps you entertained the whole time. The level where you play as a terrorist is a little strange, but you can skip it, so if you feel you'll be offended then just turn it off. Overal, the single player experiance is great, and you'll enjoy it for it's short duration.
As for the multiplayer, it's not that it isn't fun, because it is. Even in games where I got killed many times I had a great time! But the game doesn't put you in matches with players that are similar to your skills, so you end up in matches where you're a level 6 against a level 50. This wouldn't be a problem if the game rewarded you at a much faster pace on the multiplayer, but since it takes forever to upgrade your weapons, you'll often feel outgunned and outmatched. If you plan on playing with friends, know that the game will separate you from time to time and have you against each other, and setting up matches can be a pain.
There is a co-op multiplayer mode as well, and this mode is great fun in short bursts. You and a friend play in what ammounts to challenges from the story, and all play out really well. You'll have timed objectives, and you have to beat them to unlock more.
I'm not going to go over graphics and sound, since both are great. Controls are right on and you'll easily jump in and start killing people. Level design can feel a little straightforward at times, but overall they feel expansive and you'll feel like the punishment is coming from everywhere, even in multi.
Overall COD:MW2 is a great purchase, and a fun game. If you're interested in the story and it's you and a friend looking to get down on the action you'll feel right at home. Online multiplayer is difficult, and for casual gamers, might I suggest the easily more accessible Left 4 Dead 2?