To be honest, Activision did good not to go to the extremes and remodel everything to the way they may have wanted, instead they tried to keep to the standard Call of Duty experience in a different era. Some tweaks have been made, and they had to be, but all in all it's nothing you can't get used to within an hour or two of playing.
Once this game is installed, you'll find you have two games, or at least they have to be launched separately to reduce lag or something. The single player is short, and I have to stress the word short. The first time you play it through, it'll most likely leave you wanting more, much more. I should say that it rushes it's best parts like the stealth mission or the mission in which you control a fighter plane, but if I told you that I'd be wrong. I'm pretty sure now that if those missions were repeated under different circumstances you'd get bored pretty quickly, so it leaves you with just the right amount of things to do.
As I mentioned before, the single player is only one of the icons. What is the other one you ask? It's obviously the multiplayer. And I would normally leave that for the end, making a quick comment about it but this deserves much more than that, it's a game on it's own. There are differences in these two modes, as usual. On singleplayer you'll get specific points in which you'll call out airstrikes, helicopters and pull out your ghilie suit, but in multiplayer those features are intergrated into every game, as long as you're skillful enough to get them.
On multiplayer, there is a mentionable 'unique' ranking system where people see how much you've played. You gather XP from simple tasks such as killing or assisting in a kill, but you can rank up major XP by completing the large amount of challenges which get unlocked along with weapons as your rank goes up. This gives much more appeal to multiplayer, as some people can get turned off by it's aggressive nature or by the frustration it can cause, not to say you won't also get frustrated by the singleplayer on harder difficulties.
One thing I was very impressed about was the level of diversity I mentioned previously. The single player splits you mainly into two places, Russia and the Middle East with several missions elsewhere. You also play as two people, who are both in the army. One is in the SAS and one is with the Marines. The two missions which differ from the game's usual pace are not with those two. However, even with this diverse world, the variety in the singleplayer is very limited, and there are very few alternative routes to take. I would also like to point out that this is not necessarily a bad thing, as getting lost in an FPS like Call of Duty is very aggravating.
The difficulty was one of the only things to be harshly increased from the earlier games in the series. Normal shouldn't give you too much of a challenge, but any harder and you're in for one tough ride. The AI has gotten better in general, but you'll find yourself confused sometimes on why the computer chose to do that or didn't do anything much at all, as usual.
There is also a class system for multiplayer. You'll start with your five basic classes. They all have different types of guns, and are made for different things. After a little bit of playing and leveling up, you'll unlock a feature which lets you create your own. This includes choosing your bonus abilities, such as a larger life, or the more amusing 'Martyrdom' which drops a frag grenade every time you die (And frag granades are lethal to any enemies close by). Unfortunately, after getting excited about making classes, you'll soon find out that you won't be able to make much at all, as most of the guns and abilites are unlocked on later levels, some will take time to get.
I've heard the phrase 'Photo-realistic' being used for this game. This is a sensitive and debatable topic, but for the moment, let's focus on seeing if it's true. This game will only look as good as your graphics card allows it to be, but if you have a brand new one you'll maybe see what everyone's on about. It's pretty realistic, but since it's a game it'll have the usual problems such as glitching and unrealistic quantities of effects which are often created in busy and heated multiplayer battles. Apart from that, the graphics really are truly outstanding and, realistic or not, some scenes may just leave your jaw open.
The maps and layout is pretty nicely done, but I've found some of the textures to be a bit edgy, and the grass can be a total pain to aim from due to the auto-focus.
A war-based FPS with a decent story? Unheard of! Well, you'll have heard it. It's not too deep or involving, but it's certainly full of surprises and moments where it'll leave you breathless. Some of the scenes are really deep and evoking. You'll have to play the game through to understand what I'm talking about.
Music? Just right. You'll maybe not even notice it when you're in a tough situation, but that's normally when the heated music kicks in and sets the tone for the game. Apart from these though, I don't see the need to have any more in a modern war game. I do love the guitar riffs you get when you level up online.
Explosions sound just as they should do, loud. It captures the effects just right, and if I'm not mistaken you'll hear the mud of the explosion trickle downwards if you're close enough and not dead from it. Guns have varied sounds from one another, some very heavily varied. This is a nice touch and can sometimes help to identify what kind of weapon you enemy is shooting you with.
Now for the voices. I really liked the single player dialog, and I found it to be very entertaining. One thing I didn't like was the amount of voices you get on multiplayer. Your ratio tells you every time someone on the server uses a UAV, an air raid or a chopper. Now, these are useful, but when you have this saying one of the phrases every five damned seconds it can get on your nerves, just most of the deaths do.
I've said before that this game is short. What I meant was that the singleplayer is short. You could be playing multiplayer for months on end, join a clan, unlock all the weapons and basically have fun. It's up to you if you want to experience multiplayer.
Replayability is dependant of how much you liked the singleplayer. I loved it, so I did it on a few other difficulties just for fun. The average run of this game would be around 8-12 depending. That's not a lot of gaming, so you might want to play it through again if you're not bored and challenge yourself to a higher difficulty.
It's something that any person with a decent computer should own. Even if FPS isn't your thing, you might want to own this just to get the experience. I should know, as I was at first sceptical about it, thinking it had been hyped up way too much, and I was expecting something mediocre. This is far above that.