It's all about the fall.
Limbo is all about the slow descent through an absolutely horrible place. It's harsh, sometimes startling, vastly unsatisfying, and almost perfect.
Limbo is minimal at its best. There is no exposition, no words (aside from one larger-than-life sign), no real soundtrack, no tutorials. Everything you need to know about the game you will learn through subtle environmental clues, assuming of course that you're paying close attention. If you're not, trial and error will be your guide. The system of dying and retrying is amazingly forgiving, unless of course you're going for that one painful achievement, and it encourages exploration. By that I don't necessarily mean exploration of the world so much as exploration of what you can do in and with the world.
The plot, as it's known, is simply a boy attempting to rescue his sister. He awakens in a forest and proceeds to navigate through the forest, to a mild industrial area, to some underground caverns, and finally to another industrial (through trippier) area. Each of these progression is fantastically subtle, to the point where you may not realize that you're in a new environment immediately.
The camerawork in this game shines like so few other games. It's out of the player's control, which can make a game more frustrating than not, but here, everything is delivered perfectly. Each time the camera zooms in or out it is not only setting up the atmosphere, but it is giving the player the exact amount of information needed at that moment in time.
The gameplay is fairly basic, and I mean that in the best way possible. The platforming is tight, and the physics engine is perfect. There were a few puzzles that left me wondering for awhile, but they were all fair. You won't find bear traps hidden behind a tree that can't be seen, or bottomless pits that must be jumped in the dark. I never felt like a death was cheap. Frustrating sometimes, but never cheap.
All in all, I can't recommend Limbo enough. The first playthrough will probably be somewhere around 5-6 hours, but once you know the game it can be done in under two, and even fairly close to one. I still have that one achievement hanging around for completing the game with less than five deaths, but this is one of the few games that I see myself coming back to from time to time even after it's 200/200'd. It's disturbing and uncomfortable, and yet somehow relaxing.
** BEYOND HERE THERE BE (minor) SPOILERS **
To continue with my title, there's an old saying regarding skydiving: "It's not the fall that kills you, it's the sudden stop at the end." In Limbo, the end really is that proverbial sudden stop. it's the only point of the game that I take issue with, and even then it's fairly minor. In fact, the only reason I even feel somewhat cheated by it is because I had a slightly more epic finale in mind, and (since it was my idea) I obviously prefer it.
When I flew through that final pane of glass in slow motion onto the floor of the forest, I fully expected to wake up and for the game to start again. What better manifestation of limbo than an endless cycle of searching and yearning and periodically failing only to be forced to keep trying? However, as time has gone on I've come to accept the ending as it was written. I'm glad they don't answer more questions, or even give the player a hint as to what happens from there, but it's still somewhat dissatisfying compared to the ending I had concocted in my imagination.