After two hours with Peace Walker I absolutely hated it. Were it not for it being my first and only PSP game, and having no other options on my commute at the time, I probably would have written it off not long after that. The game basically attempts to replicate PS2-era MGS, particularly MGS3, on the tiny confines of the PSP. It does a very fine job of this in all respects, except for the camera, owing to the fact that the PSP does not have a second analog stick. Given the small environments, you'd expect some sort of camera like in MGS1 that tracks with you to some degree, but no - camera control is still 100% manual here. And there's basically only two ways to do this - either assign the camera to the D-pad, which requires you to take your thumb off the stick to adjust it, or assign it to the Triangle-Square-Etc. buttons, which means all actions and weapon use moves to the D-pad, which means to do any of that you have to take your thumb off the stick.
It's really a terrible system. The game's bite-sized nature, however, makes adapting to it possible if you're willing to put in a few hours of frustration. If you haven't played predecessor Portable Ops, the game is best thought of as something like the VR Missions disc for Playstation, basically a collection of mini-missions that you choose between and play freely with a whole lot of "fanservicey" stuff sprinkled throughout. There's a story mode, but the story missions are broken up into chapters just like all the other optional missions, and you're free to take the chapters on at your leisure, or pause on them for a bit and just play some of the "extra ops" instead. All these missions - both story and optional - take place in a fairly small range of settings, and these settings are re-used a LOT throughout all the new missions that are unlocked. Guard placement and patrol patterns don't vary a whole lot between missions, so once you learn the layouts by playing missions a couple of times, you anticipate where the guards are and where your view needs to be and move the camera ahead of time while still in a safe area. The game is immensely irritating until you get to this point, but once you do, it actually becomes quite playable and enjoyable, and a rather impressive depth of content unfolds for you.
So I ended up clocking something like 40 hours into it instead, once all was said and done. The game's main story - the tale of Big Boss forming the nascent version of Outer Heaven with his mercenary group Militaires Sans Frontiers as they set up a base in Costa Rica - takes up only maybe 10 to 15 hours of that time initially, but to get the "real" ending, you're expected to complete the 100-odd "extra ops" that are gradually unlocked as well as going through all sorts of other rigamorale. The game hooked me enough to actually make a run at this, but for various reasons I ended up hanging it up well short of the goal.
The main story is your usual Kojima tale full of military jargon, goofy fourth wall breaking and plot twists, but surprisingly free of Codec calls, long-winded cutscenes, and superpowered boss enemies. The fledgling Militaires Sans Frontiers strikes a deal with a KGB representative - in return for a disused offshore base and A Choppa to ferry themselves around in style, the MSF will look into a mysteriously high-tech group called the Peace Sentinels that sort of just showed up in Costa Rica out of nowhere and appear to have ties to the CIA. As the investigation goes on, of course, things get much more complex, and you end up battling a whole shit ton of tanks, troop transports, helicopters and bizzare high-tech AI machines that seem to have a will of their own.
The story is surprisingly good. Yoji Shinkawa, the cutscene artist with the "sketchy" style who's been with the Metal Gear Solid series since the first game, gets a chance to shine here doing the cutscenes between missions entirely in an animated manga style that works really well. The graphics are about the best you can hope for on the PSP and nearly PS2 caliber, and the game has a really excellent soundtrack to boot.
The main problem is the post-story content, or at least the giant gap between the end of the "main" story and all the nonsense you have to go through to actually finish the game. A lot of the "extra ops" missions are fun and creative, for example hunting violent ghosts to take their picture, or defending zones against an onrush of enemies in Timesplitters style. The problem is that just after you finish the main part of the story mode, it seems like the fun and creative missions stop trickling through to you, replaced by a shit ton of samey battles against tanks, helicopters and troop transports that are virtually identical save that they get harder-hitting guns and more ammo each time. Aside from just being repetitive, there's also a point where you really don't have the equipment to contend with them anymore, and the only way to get it involves just ridiculous amounts of grinding.
Grinding is a major theme to this game, apparently due to Konami/Kojima's weird determination to horn in on the Monster Hunter audience with this one, and it takes a number of different forms. In between missions you are constantly building up MSF's home base in a number of ways - recruiting new soldiers, making more money, and having your R&D department create new weapons and items for you. You need soldiers to make money, so that's the first step. You can connect to open WiFi points to get some randomly generated ones once per day (per point), and if you have access to the Playstation Network via PS3 you can trade with other people, but the primary means is playing old missions over again to shanghai enemy troops using the always amusing Fulton Recovery System. Soldier-grinding actually isn't that bad, you tend to get an adequate amount just playing the missions and hitting up a WiFi spot here and there, but document-grinding is a real pain in the balls. Before your R&D department can add any new weapons or items to your inventory, even a humble banana, you have to first find their blueprint somewhere in the game. Sometimes they are laying around in certain missions, but more often than not - and especially for the really good and useful ones - you have to "earn" them by S-Ranking a mission or completing one of those godawful repetitive overpowered boss battles I mentioned previously. You also have to grind up your weapons to get them to their optimal state, which simply entails hours upon hours of use (seriously, most take a ridiculous amount of time to level up.)
You hit this sort of Catch-22 point eventually where your existing weapons are too shit to take on the optional boss battles that are available, but to get better weapons you have to beat those battles. A major contributor to this issue is that Konami, by their own admission, did not scale boss battles down in difficulty for a solo player. The game's multiplayer component is great - generally up to four people can complete the "extra ops" together - but battles are programmed as if you'll always have 2 to 4 people available. If you're playing solo on the bus or something, you are effed and then some when you hit about the point that I did when I gave up on the game. With 4 people pounding away with shit weapons the boss battles are doable, but one person with janky camera has next to no hope of pulling it off.
This really reflects how Peace Walker was seemingly designed solely for the Japanese market and then ported to the Engrish-speaking world as an afterthought. Oh, the localization is great, the dialogue is well-written, and the voice acting is on par with the usual caliber of MGS. But ad-hoc teamwork play is way, way bigger and more common in Japan than it is anywhere else, as is Monster Hunter-style grinding.
Thus, the game ends up being such a mixed bag. If you have friends with PSPs who will get the game and play with you consistently, or if you have a PS3 and can connect to play with people online, the game is a recommendation without reservation. For people mostly going it solo, however, it's a much tougher call and probably depends on a combination of your love of the Metal Gear Solid universe and your level of patience for finicky, demanding games. I usually hate finicky, demanding games, yet I found enough here to make the game worthwhile, but I was also very disappointed that the game basically gave me access to 90% of the story but effectively shut me off from the final 10% unless I scratched up some friends with PSPs or shelled out for a PS3. Camera funkiness aside it's a very well-polished, well-made game with an almost startling amount of depth and still probably one of the best overall for the PSP, but it's hyper-quirky and pitched primarily to an audience that doesn't read this language.
* Gameplay Video