Uncertain of his sister's fate, a boy enters Limbo. That's the remit. Those are the only words you'll get before watching a bright-eyed youth wake up in a silent monochrome world and valiantly set out from left to right.
As you do so, it isn't long before it dawns on you that what you're playing is in all likelihood a classic, liable to be mentioned in the same breaths as Portal or Braid, potentially even Another World, a game whose sensibilities Limbo certainly shares.
On the surface it's a somewhat snooty puzzle platformer - inspired by German Expressionism and Film Noir, it's easy to confuse it for a lesson in pretention from a developer who's spent longer sitting in an arty cinema than making heads explode.
It is, however, one of the smoothest, most refined and charming games that will be released this year. Originating in a tentative animation put up on the internet three years ago by its Danish creator Arnt Jensen, a small industrious team has grown around it - polishing it to a high sheen for a summer 2010 release on Xbox Live Arcade. One dedicated Dane has spent three years on the movement and animation of the boy alone.
Said boy - a cross between Calvin out of Calvin & Hobbes and the ancient image of a Game & Watch character silhouette - must walk, climb, grab and drag his way through the bleak surroundings, facing down frequently deadly puzzles.
There is no bombastic music. Sometimes there's little to do but wander from hillock to puzzle in pleasant silence, with only your footsteps, the occasional bristle of wind or suspicious cracks emanating from the undergrowth to serenade you.
The paucity of sound effects and the relatively barren screen condenses the gameplay into seemingly simple tasks, but it also envelops you - almost drowns you - in its minimalist loveliness.
And then, just when the German art-house cinema stylings and foggy sheen have transfixed you, the boy's head is cut off. Dark glops of silhouette blood go everywhere. His decapitated corpse jiggles in the breeze.
It's absolutely hilarious. He drowns, snaps, gets caught in whirring machinery, finds himself pierced by a vast and grotesque Shelob-style spider right in the face... He dies for your pleasure, with physics-attuned animation both grotesque and brilliant.
The last game that had this much fun with gruesome traps is Lemmings - and the hungry mantrap jaws the boy stumbles into, and the way his guts cling to the masonry that's crushed him, are surely references to the halcyon era of DMA Design.
The contrast between the utter joy the game has in ripping its little hero apart, and its apparently high-brow stylings, make it a genuine laugh riot. When you come across something that looks vaguely sharp or pointy you'll inevitably kill that boy in Limbo, just to watch him die. Checkpoints are regular as clockwork, so death rarely becomes a frustrating commodity.
So what, exactly, do you do in terms of platforming? Well, the controls are simply the 360 analogue stick and a grab/do button; the game's keymap option screen is a minimalist joke in itself.
An early, simple puzzle has you come across a corpse that's buzzing with flies hanging from a rope attached to tree branch, and unreachable platform above it. Your task is to manoeuvre a nearby mantrap beneath the mouldering body and leap onto the rope - dragging down the tree bough, dipping the maggot-filled legs into the waiting teeth of the trap, and once the body is detached swinging on the rope to freedom (of a sort) on the ledge above.
Rotten trees can be pushed over, and rolling boulders that thunder towards you must be dodged, but repetition never becomes an issue. As each new puzzle emerges from the gloom neat twists on existing gameplay veer your problem-solving in different directions - one minute you'll be snapping off arachnid legs with your mantraps, the next it will have cocooned you Frodo-style with its web and all you can do is hop over the landscape as if trapped in a zipped up sleeping bag while desperately trying to avoid the rolling architecture.
Later on, as scenes become more urban and industrial, vast moving cogs and magnets come out to play, the screen starts to revolve around you and… spoilers, spoilers, spoilers. Needless to say, Limbo isn't quite as trapping and motionless in its approach as its name might suggest.
If there is a worry about Limbo it's that its puzzles might become too complex in the closing stretch of its four-hour runtime, yet the first 40 minutes I've played this year at GDC are user-friendly in a way that only the most incessantly playtested games could ever be.
The way the game nudges your attention to relevant puzzle items through the usage of butterflies, rumbles, falling leaves, subtle camera-points and the movement of the boy's beautiful glowing eyes is fiendishly clever, and the deaths associated with them rarely anything but stabby/shreddy perfection.
Above all, Limbo is mysterious - and developer PlayDead wallows in the mystery. Is the boy dead? "Maybe." Was that his sister on-screen? "Who knows?" What more can you tell me about the story? "Uncertain of his sister's fate, a boy enters Limbo." Do I need to get something to float on this water so I can stop drowning in horrible ways? "Who can say?"
The only thing I can nail down here and now is that Limbo already feels like it will be up there with the most interesting games of 2010.
Limbo is due out exclusively for Xbox Live Arcade this summer.