Everything you expect. And then some.
Campaign
If you've played any Call of Duty game in the past 4 years, then you are probably well aware of the kind of high octane story telling that this series brings to the table. For those who are not, Modern Warfare 3 follows this tradition by throwing you headlong into the fray, at top speed and does not let off from beginning to end. If you aren't in the middle of a fire fight under the shadow of the Eiffel Tower or a war torn London then you are witnessing some of the most gripping cinematics in games or film.
Of course, how else could you frame World War 3? Doing anything less would be an injustice to the kind of global scale the series is known for. And you will be spending plenty of time around the world. You will be hitting almost every major city in the world in search of the man who orchestrated it all, Makarov. You will still get to spend time with everyone's favorites "Soap" McTavish and Captain Price but you will also be able to jump into the shoes of elite Special Forces from around the world. While the engine isn't nearly as powerful and detailed as Battlefield's Frostbite 2, it is plenty powerful enough to put you in awe of the destruction taking place. In some ways, the lack of focus in perfect detail allows for a little bit more artistic freedom in things like using lighting to set the mood.
The story itself is just as grand as ever but with the story arc coming to a close, less room is left for the sweeping surprises from the first and particularly the second games. However, don't take this to mean there aren't any, just nothing (yet) that will throw the story line into a tailspin.
Spec Ops
Spec Ops makes a return but this time with the bonus a survival mode (and be honest, those were your favorite missions from MW2). The original mission style Spec Ops from Modern Warfare 2 returns allowing you to try to achieve certain missions sometimes of an unusual nature. All of these missions take place in areas you visited during the campaign but allow you to do things outside the story or perhaps to the role of the enemy instead. Any fan of Modern Warfare 2's Spec Ops should feel right at home. The survival mode is the really interesting part. You can play this mode with only one friend and you can play on any Multiplayer map in the game. At first you may think that only having one companion is taking a step back from the Zombies mode from World at War and Black Ops but it makes the stakes far greater. I should first point out, though, that this isn't meant to be like Zombies so expect a different, more strategic tone.
In essence, this is an endless survival mode where the only way out is to die. There end the similarities with Zombies. The lower team size means that you will have to pay very close attention to your teammate. If they die, you will be alone and very likely on your way to joining them so make sure to watch their back and doubly sure to help them if they get downed.
This game mode borrows a page out of the Horde 2.0 handbook by giving you far more options than just weapons to throw your cash at. You won't find anything as drastically Tower Defense as razor wire but you will be able to buy up to two auto-turrets, air support, or AI controlled reinforcements. You, of course, can also buy weapons and ammo but it's rather unnecessary unless you are really attached to a particular weapon. You only start off with a pistol but enemies will of course be bringing you large supplies of weapons and ammo in the near future which really limits the improvement you get from buying newer weapons and/or ammo.
This is by far the biggest improvement in this game and one of the reasons why I wouldn't just shrug it off as just another Call of Duty game. It adds a tense level of cooperation that you don't generally see in the series and can in some ways almost feel like an entirely different game built using the same engine. But don't fret, it is certain to keep your adrenaline pumping just as well as any other game mode.
Multiplayer
If you are like many gamers, the campaign is what originally brought you to Modern Warfare but the Multiplayer is why you stayed. This installment will be no different. The core of the multiplayer is still here. You make your class with your favorite load-out, you spawn, run around and try to find enemies to kill. All your favorite game modes are still around and then some. What has really changed is the customization of kill streaks.
Before, it used to be that if you managed to kill x number of enemies without dying, you were rewarded with some form of kill streak and you could pick and choose which kill streaks you wanted to use. Both aspects of this have changed. There is no longer just one list of kill streaks (now called Point Streaks) from which to choose but three, Assault, Support, and Specialist. Assault is the list that most Call of Duty vets will be most comfortable with and encompasses the various kill generating streaks like gunships and attack dogs. Support includes streaks that your entire team can benefit from like the Counter UAV as well as body armor that you can drop on the ground and share with your team. Specialist is completely new and allows you to gain additional perks for your point streaks instead of one time use streaks from the other two lists. And how you collect point streaks is a little different too. If you go with Support, any support action like getting an assist will contribute to your streak and death doesn't immediately destroy your streak allowing for the support class to be more consistent. The separating of Assault and Support haven't really changed gameplay in any significant way beyond how you generate points towards them but the Specialist class could be particularly interesting/devastating in the hands of a very good player. Unfortunately, we haven't hit the point where it's possible to see that yet.
There are a couple of new game modes worth mentioning. Kill Confirmed is a new game type that involves killing your enemies and then collecting their dog tags. In this mode, only collecting enemy dog tags will contribute to your score. This means that camping is only a good tactic if you're doing it in support of another player who is collecting tags because otherwise the kills will go to waste. If you get a kill and you aren't fast enough, the enemy team can retrieve the dog tags of their fallen comrades (you can do the same for yours) to "deny" your kill. In other words, it removes the tags from the map, keeping you from scoring them.
The other new interesting game type is Team Defender. Whenever the first kill is scored in the match, the person killed drops a flag. The team who holds that flag receives twice as many points per kill as the team that does not. This causes an interesting mix of objective and team deathmatch game play where you want to try to get the flag so you can gain more points but you have to do so while being much more efficient than the other team, lest you give the other team a huge score lead. Most other new game modes have already been done and are based on modes from other games such as Drop Zone which requires you to hold a drop zone to get bonuses like care packages which is similar to Halo's Invasion Slayer. I could go into greater depth on these but they have all been included into the game for good reason. Both Gun Game and One in the Chamber make a come back from Black Ops and Infection and Team Juggernaut join Drop Zone as borrowed game types.
Lastly, there are weapon proficiencies which allow you to actually become better with each weapon. You will level up with your use of any given weapon allowing you to do things like reduce recoil or loss of accuracy when you're shot. This allows for a greater fine tuning of your classes and compliment perk choices nicely.
While I could go into great depth on things like perks, attachments and changes in how weapons act, it would be rather futile to do so. How things are balanced is a matter of taste but I do think I can safely say that Infinity Ward has listened and adjusted things based on feedback for the most part. Otherwise, the core gameplay is the same. You are still picking weapons, attachments, streaks, and perks and you are still running and gunning
Social Integration
This is important enough to get a category for itself. There isn't a significant amount to actually say about this because it's all a matter of how you use it but it's still incredible. Modern Warfare 3 supports integrated social network functions.
First of note is Call of Duty Elite which is a service run by Infinity Ward in two flavors, free and premium. It will be a resource for checking all of your stats online, meeting up with players, forming clans, and taking on clan missions. Beyond that, it will also be host to instructional or informational videos from professional gamers about the different facets of the game, hopefully giving you a greater edge. To help you get an idea of how you play, they've included heat maps so you can figure out where you get most of your kills and deaths on any given map.
Beyond that, you'll find integration with Facebook that allows you to interact with your friends there. The most important part of this is that it essentially allows you to create a secondary friends list for the game that uses your friends on facebook. I think that once the game gains traction, it will make it exceedingly easy to find people to play and it's a move that a I sincerely hope other developers catch on to.
Graphics and Sound
Modern Warfare 3 is the crispest, best looking game in the series yet. The effect look great with water spraying all over and adding a sheen to character models. Trees look fuller, buildings reach into the sky and rocks litter the streets. The textures, proportions, and wire frames of character models are superb and the animations are far superior to Modern Warfare two. It isn't the most exceptional in terms of pure graphical prowess but conveys feeling with a depth you'd expect from the Modern Warfare series and is still rather impressive considering it keeps a steady 60 frames per second.
The epic, moving scores of the previous games coupled with great new sound effects amplify every aspect of the game. Every gun sounds deadlier, every mission feels grander, and everywhere you go sounds like it's about to fall apart. I am a firm believer that a good sound track can make or break a game and I'm happy to say that in this area, the game succeeds very well. Occasionally the music comes over a little too strong, making you aware of its presence rather than staying in the background providing an unconscious ambiance but on the whole, it excels at making you worry about what's coming without tipping you off completely.
Age
Some people might call this unfair but after have five installments in just over four years, I think it bears mentioning if simply because you have every right to let this affect your buying decision. The gameplay is still great fun but it still hasn't changed in any significant way. In fact, if you took this game and a previous game in the series it gave it to someone who has not played a Call of Duty game before, I suspect you'd be hard pressed for them to figure out which one was the newer version with anything less than 100 hours of gameplay time. Yes, the game has been improved but it's really only been improved in nuances. With that said, it's still exceptionally fun.
Conclusion
It's fun and the story has a conclusion. Spec Ops is enough of a departure from Zombies that I would expect it to be wholly satisfying for those who prefer co-op to the exclusion of Multiplayer. While I would still be skeptical of buying this if you have Black Ops already, it would still be worth getting for how much fun you can have with your friends. And if you are considering making this your first Call of Duty purchase, I can whole heartedly recommend it but under one condition. You should play Modern Warfare 1 and 2 first because the story, while functional on its own, isn't nearly as coherent without the background of the previous two. And you can probably pick them up used online for pretty cheap.
I'll be giving this game a 1.0 deduction mostly just for the age of the game. I would like to give it a larger deduction because in some ways I feel cheated by the lack of change but at the same time, it really is just too much fun for me to give it a lower score. But despite the fact that the game has been done before, I can't say that the fun has diminished, merely the number of hours I'll be playing it.