The review system is being buggy just now, so here's my review in a handy dandy blog post!
Metal Gear Solid 4 follows series protagonist Solid Snake, now Old Snake due to accelerated aging caused by him being a clone. He has been sent on a mission to stop Liquid Snake, somehow surviving his demise from the first game and possessing Ocelot's body via a transplanted arm in the second game. The world is a grim place, where War is the main economy for the world, with countries making and losing their money via weapon sales and PMCs all controlled via nanomachines. Liquid is planning and insurgency, despite the fact that the moment he tries the nanomachines in his soldiers should cause all their guns to stop working. So naturally, everyone is pretty scared of what he has learned. The story overall is pretty good, and is a good conclusion to the Solid Snake saga of the MGS series (I still think we'll see more prequels telling the story of Naked Snake/Big Boss though.) However, the story feels very heavily condensed, put into frequent cutscenes that often break the hour mark and tell things in an unelegant and honestly rather ham-fisted way. While the game does answer all the questions from previous games, it does so in a seemingly random way, where explanations for things from the previous game are slotted in where they don't seem necessary. There's also the fact that characters act very unnaturally in many places, especially Naomi. Overall the story feels like it should have been split between at least two games rather than all crammed into one. The story is good though despite these issues. The best part of all is Old Snake himself. Old Snake in MGS4 takes on a similar role to Naked Snake in MGS3, he isn't really doing the right thing, he's just obeying orders, and he is beginning to come to terms with big changes in his life. In MGS3 it was The Boss's betrayal, in MGS4 it's his impending death. It's one of the more well conveyed parts of the MGS4 story, and makes Snake a much more likable character than he otherwise would have been.
Luckily, Snakes age doesn't impact his maneuverability much. He's still quick to move and react, his aim is still steady and he's even picked up some nice CQC techniques in his time since MGS2. You find a large selection of weapons, with playing the game as a shooter becoming more of a viable option than it use do be. However you can still play it stealthily if you want to (and I did) for the most part. In general it plays like the last game in the series, MGS3 with a few key additions. Octo-camo dumbs down the Camo system from MGS3 for people who didn't understand it or something, the Drebin Store lets you buy ammo and weapons on the fly at any time you feel like, setting a very different feel from the previous MGS games. In the older MGS games it was not uncommon to run out of tranq ammo and be forced to play differently to compensate (if you were like me and only tranquilized people that is) but that never happens here. ever. Overall though it's still MGS, the mechanics till work great and the AI is improved a fair amount too. This is great for the two chapters of the game where stealth is important. Yes. Two chapters. You see the game is split into 5 chapters. The first two of which are utterly fantastic, they have a few minor issues (respawning enemies? What?) but overall they are a lot of fun and they feel like they are a great evolution of the MGS mechanics. The other 3? Not so much.
The third chapter consists of a terrible section where you follow a guy through a street and then an on rails segment, which while not necessarily bad, has been done better elsewhere and really only exists to fuel nostalgia for MGS3. The fourth segment takes place in a setting of a previous game, and all the enemies you encounter are machines, which makes it super-easy, since one chaff grenade and they're all out. Or, you can fun your way through them much easier than humans. "But Protome" you are no doubt saying, "I want to finish MGS4 without any kills to unlock bonus stuff!" Don't worry! Killing machines doesn't count. So just run and gun your way through this dull section, which again, only exists to fuel nostalgia. Then there is the final chapter, which is okay. It's more similar to the first two chapters, but is also really short and has the worst cutscene to gameplay ratio.
Thats one of the main issues with MGS4 as a whole, and personally is what I think caused all the great reviews for it to occur. MGS4 plays on nostalgia for the franchise all the time, constantly making references to the older games, bringing back characters or locations or gameplay sections. And honestly, I think it's a poor idea. You can't make a game solely based on nostalgia, nostalgia isn't fun. And honestly most of the references to older MGS games just served to remind me how much better those games are than this one.
One thing that MGS4 does just well as the previous games however is the boss fights. Bringing in the Beautys and their Beasts, a group of female soldiers who have been enhanced by machinery to have crazy powers, and nanomachines that force them to feel one emotion. They are great characters in their own right, and fantastic boss fights which successfully do what the rest of the game wishes it could do. They play on nostalgia of fans by basing each of these bosses roughly on a boss from the first game (often only in name) but these boss fights are good enough to hold their own and stand up as some of the best boss fights in the series. They don't rely on nostalgia to keep players playing like the rest of the game.
MGS4 also has a big online component, which is pretty fun, and a good evolution of MGS3 and MGS Portable Ops' multiplayer components. That said, it's not really as good as some of the better multiplayer games out there, but it's fun to kill some time in.
So, to sum things up, what do I think of MGS4? Well, I really love the first couple of chapters. But that's 2/5ths of the game. The final chapter was good too, so that's 3/5ths, but the other two chapters were abysmal. If 2/5ths of your game is shit, you're doing something wrong, simple as that. The game has same great mechanics, but has very few sections of the game where those mechanics are used well, and relies too much on nostalgia to make up for the dull parts. It's worth playing to see the conclusion to the story if you are a fan and are willing to overlook some really bad parts of the game, otherwise, skip it. Maybe watch the ending on youtube or something and go back and replay MGS3. 'cause that game is awesome.