With no major music, story, and the only colour on-screen being grey, it's amazing how immersive this game actually is.
There isn't any accompanying music setting the mood of the game either, apart from the rare loud note to accompany certain events. The foreground is black, and the background is various shades of grey. There's even a graining effect like the kind you get on old film footage. No heads-up-display, so no health, no energy or anything. The lead character (actually one of the few characters in the whole game) is a small boy, coloured head-to-toe in pure black with two pin-pricks of pure white light for eyes. He can run, jump, push, pull and grab stuff.
At this point, you would be forgiven for thinking what the point of a game with these qualities is exactly. As I already said the designers want you to figure out the start and finish for yourself. But what the game does present you with, is the journey in-between. That journey takes place in one seamless world; from start to finish there are no visible loading times except when the game first loads up. The environment may be grey, but it's full of detail, both in the foreground and backgrounds through the fog. There may be no music to speak of, but there are sounds; the boy's footsteps across the ground, crickets in the grass, running water, falling rain, creaking wood, and the absence of music simply serves to make those sounds stand out further in the silence. Usually when a game goes quiet (like Resident Evil) it means something awful is about to happen. That feeling is with you every step of the way. Limbo is one creepy place to be.
Or should I say, survive in. There are no end of things either trying to kill you, or worse, waiting quietly to kill you. Spikes impale you. Bear-traps slice you into pieces, as do buzz-saw blades. Pistons and gears will crush you. The occasional inhabitant will attack, although this is very rare. Submerge yourself in water up to the head and you'll drown instantly (and no he doesn't float). And the boy's death animations, while not highly detailed, do more than drop a hint; blood splatters and occasionally flying body parts are accompanied by prominent sound effects. When you fall from too high, the bone-jarring crunch is enough to make you wince. Actually most deaths will make you wince, even after you've seen (and heard) them all fifty times. And you will die frequently until you learn to get round the problem in front of you. Fortunately the game's checkpoint system is very forgiving, and you will never have to navigate one puzzle or some awkward platforms just to get to the one you failed.
The puzzles themselves operate with simple items, such as switches, blocks and ropes, but none of these elements are used too frequently and are always arranged differently. One interesting mechanic is the (very occasional) glow-worms that land on the boy's head. They attach themselves and force the boy to move in one direction only, until you walk or run into light, at which point they turn you around. And you can't stop unless you grab or walk into something solid. There's also the switches that change the direction of gravity for the local area, and water can flow from place to place and allow certain objects to float, as well as providing a drowning hazard.
I've tried to come up with some words to describe this game. Strangely, 'enjoyed' doesn't sound quite right to me. Because this game is so unique, it's difficult to know where to set the benchmark. Limbo hasn't carved out a niche for itself. It's brought its own niche with it, and nailed it to a shelf no-one else knew was even there. Along with a new benchmark. 'Glad I played it' sounds better. 'Good' isn't right either. More like 'unique', 'special' or 'immersive'. One thing's for sure; you've never played anything like this before.
... wonder if they'll do a follow-up called 'Lust'? Just a thought...