Like the titular realm, Limbo is neither abhorrent nor wonderful.
Ah, Limbo. It has been called this year's Braid; a masterpiece; perfect, even. Let's have a look-see, shall we?
Limbo is a puzzle-platformer. And I'm going to address the game's largest problem immediately: Both the puzzles and the platforming are completely devoid of any challenge. The former virtually never require more steps than can be counted on one hand -- move a box, pull a lever, climb a rope and you're done; that's roughly how most of the puzzles go down -- and since the tools needed are always clearly visible and the way in which they are to be used always immediately apparent, the only thing being tested -- unless, of course, you're an idiot -- is whether you possess a pair of eyes and the physical strength needed to move the analogue stick and press A (jump) and X (grab). The latter demands extraordinary feats of neither precision nor timing; if you can play through the first level of Super Mario Brothers, you'll breeze through even the hardest of Limbo's platforming parts.
(You will die, however. You might wonder how this is possible when the puzzles are easy and the platforming easier. It's quite simple, really: The developers have implemented a number of trial-and-error challenges; parts in which survival is nigh impossible unless you already know what's ahead. I find this decision very puzzling. The game's checkpoint system ensures that you always reappear mere seconds away from whatever hazard killed you, and the aforementioned challenges are just as easy as -- if not easier than -- the rest of the game once you know what's coming, so all these trial-and-error parts serve to do is waste your time.)
So if there is no challenge to the game, what is there? Not much. The monochrome graphics look quite nice -- the animations are smooth, and there are some really neat-looking multi-layered backgrounds and depth-of-field effects -- and the sound design isn't half bad, but it is by no means a visual or aural masterpiece on the same level as Vanillaware's Muramasa: The Demon Blade or Konami's Castlevania: Order of Ecclesia, or even fellow Xbox Live Arcade games like Braid, Metal Slug 3, Geometry Wars: Retro Evolved and others.
But I must mention that while there's nothing exceptional about Limbo, there is nothing particularly terrible about it, either. It's not broken, it doesn't waste your time with boring tutorials or needless exposition, and the controls are both sharp and responsive; however, not being bad does not equal being good (something people who declare games like Portal and, yes, Limbo "perfect" don't understand), and I cannot with a good conscience recommend Limbo to anyone but the most devoted puzzle-platformer fan, who makes it his mission to play any and all entries in the genre. If you aren't that person, there are much better games to spend your money and, more importantly, time on.