I'm not one for reviewing things, but when I see great potential wasted, I can't help but say something. That's the exact problem with MW3. Initially it seems like a great game, weapons sound very beasty, graphics are great for a PS3 title, and it has about everything you've come to expect from a Call of Duty game. My favorite new feature is their survival mode, where it's fighting against waves of enimies, which later on get real tough, there's no ending to the assualt, much like Treyach's Zombie modes for their Call of Duty titles.
However, this mode was met with a great intial idea but never built upon, never expanded, and so you have little to no DLC, no updates to improve the modes and what you're left with is the desire of wanting more but instead find that requires you to buy their next title aka this game was popped out and forgotten.
Since they've abandoned this title, which really makes me mad, I see so many little things that could have made this an easy 5/5 game if only they had spent a little more time tweaking it, etc.
I can't say much for the storyline, or anything else, it's a Call of Duty game, you know the basics, and they bring those basics... What they don't bring is variety, creative design or a dedication or devotion to their titles... Infinity Ward have forgotten this game and with it goes so much potential replayability that could've existed. To end this review I'll give an example why I despise the design for the new Survival game mode, despite how much I loved it at first.
When you begin you have like no money, then as you progress through the stages you eventually get rich beyond belief, so much in fact there's nothing to spend it on... There's certain "upgrades" and "support" you can get which at first helps to easily drain your funds, but later they prove obsolete both in wasting your money and in providing any help. I would've loved to be able to upgrade my weapons with cooler mods to my guns, like a double drum magazine for my AA12 shotty, or get juggernauts to replace my Riot/Shield squad... or getting a Juggernaut suit for a further upgraded purchasable armor, maybe having the ability to upgrade my turret, or get more of them despite it costing me perhaps 2.5x the amount of the first one.
Instead I just pile up my funds with nothing to spend it on and take on impossible unrealistic odds with enemies that take 2-3 headshots to kill, who don't even have helmets on. The enimies never get creative, all they do is get more health where eventually it takes too long to kill them and the fun replayability is lost and the variety is found to be too limiting. No DLC to remedy these issues since the developers want your money not your satisfaction. The game ends up having a cheap, uncreative way in increasing difficulty... Something a tripple A title should never have, it's completely unacceptable. The game itself is nothing but average, it had the potential for a 5/5 if only the developers cared enough to invest their time into making it as such.
P.S. it's at a low price, consider getting it if you want to finish the storyline from the 1st and 2nd, but don't expect anything great, otherwise you'll be sadly mistaken and disappointed.