Most people have heard of the 15 puzzle (though maybe not by name), a puzzle containing fifteen numbered sliding tiles and one empty space; your goal in solving it is to restore all fifteen tiles to numerical order. Your only tool in achieving this is the ability to slide a tile in one of the four cardinal directions, to empty space (for the purposes of this tale, we'll ignore the additional and much-loved screwdriver option.) Even if you aren't familiar with the physical object, the 15 puzzle's virtual offspring has found its way into many a game as a minigame distraction.

Hudson sent a pair of these puzzles, with art from the game instead of numbers on the face, along with my Wii and DS review copies of Rooms: The Main Building. While the physical puzzles function exactly the same as those I've been familiar with since my childhood, Rooms proper is something else entirely. It takes this simple concept of sliding pieces around into a new arrangement and morphs it into a brand-new experience.

Rooms has a bit of a creepy backstory, featuring an anthropomorphic book with an unsettling laugh and the tendency to give explosive birthday presents to well-dressed gentlemen, sucking them into alternate universes. Mr. Book does just this to your avatar, Mr. X, who must then solve a number of sliding puzzles that he himself is a part of.

Unlike the 15 puzzle, in Rooms you can only move the room that Mr. X is currently inside. Each room has a number of features, which can range from impassable walls on any of its four sides, to locked doors, keys for locked doors elsewhere, telephones that teleport, wardrobes that swap rooms, water that floods a room (and a hydrant that can be used to pump said water in one room and out the other), and several other neat and occasionally brain-bending things. Mr. X can only move sideways or climb up and down ladders; you'll need to slide the rooms around until you can get him where he needs to go and eventually to each puzzle's exit.

There are 100 puzzles in Rooms' main game which run the gamut from dead easy to, on my DS, "still not solved." You'll have to solve the majority of earlier puzzles to move on to later, though there are some built-in opportunities to skip. There's also an homage to the picture version of the 15 puzzle built-in to each level, with background pictures in each room that must be aligned properly to get a gold medal for each stage, as opposed to just getting to the exit for the silver—this proved particularly adept at pushing my perfectionist buttons, leaving me raging at a patch of gray on the level map and jumping back in to try again.

It's a pretty ingenious game design, really. It perhaps can get a little too confusing as things ramp up, sometimes; my poor aging brain can only process so much at once, and when you've got gimmicks in every room and rules to remember for each, sometimes the mental process just breaks down. But then I'd crack one particular "how do I get this room over here" nut, the light would go on, and I couldn't help but feel accomplished. It's got just the right balance to be addictive.

Going from puzzle to puzzle is spiced up slightly with the rather bizarre story; you'll find items on your way through the rooms that can be used in little side-areas to play out some more crazy goings-on and unlock further collections of rooms. It's nice to break things up a bit, but ultimately a sideshow to the main attraction. The music is well-suited to the game's city-at-night atmosphere and the aforementioned tales.

Both versions of the game offer the same gameplay, and even both sport level editors (the Wii version will hold 100 levels for you; the DS version 10—and while you can trade levels locally between DS copies of the game, the Wii version has no trading functionality I could find, despite what the back of the box claims.) The Wii version also has a two-player battle mode with its own set of 20 completely new stages where you'll race to be the first to solve your symmetrical side of the puzzle and get to the shared exit. You can't actually affect the other player, but that's probably for the best, lest the match devolve into interminable chaos.

The Wii version also suffers a little from blurriness when played in widescreen. Part of that is, to be sure, Wii's fault with its scant horizontal resolution, but I think a larger font would have helped things immensely. Thankfully, you don't lose anything by switching to fullscreen—definitely do this. Both versions suffer a little from occasionally difficult-to-identifiy gimmicks, particularly doors; but they're not impossible to spot with a careful eye. Between the two versions, I prefer DS; though it doesn't have quite as impressive live-action animation as the Wii version, it's still quite good and feels right at home there.

I really like what Rooms has done for sliding puzzles. I wondered initially if it would prove to be worth its retail asking price; I think that between the plethora of puzzles, how it twists up my brain in new and enjoyable ways, and the bonuses like the level editor and unlockable time- and move-limited challenge modes, it comes close, though $30 feels a touch steep in 2010. It's a delight for the fan of the thoughtful puzzle game, though, right at home on the DS and showing off its beautiful atmosphere on Wii.