For many, sliding puzzles are synonymous with cereal boxes and cheap Christmas crackers. Usually they'll sport a picture of a topical film hero or cartoon character, and they're nearly always encased by crude and colourful plastic. In video game form, sliding puzzles are rarely used as anything more than throw-away mini-games. With Rooms: the Main Building, however, the classic sliding puzzle has been given the lead role, with Hudson Software building an entire game around the mechanic. Aside from being offensively ugly, which I'll justify later on in the review, Rooms: The Main Building offers something different enough to give puzzle fans a reason to take notice.

The game offers over 100 puzzles built around the slide mechanic, with an attempt at a narrative to stitch them all together. Players step into the shoes of the ridiculously named Mr. X, who is transported to a peculiar mansion after a mysterious invitation arrives at his house. With the help of Mr. Book (who is indeed a book), Mr. X must work his way through the room-based world, and solve the mysteries of the mansion along the way. Why the developers felt the need to wrap the puzzles in such a superfluous narrative is anybody's guess; the game would have worked far better without all the detective guff masquerading as a story. Regardless of whether you decide to pay attention to the plot or not, the objective of the game remains the same; to guide Mr. X through the game's mansions and back to his normal life.

The aim of all sliding puzzles is fascinatingly simple; to rearrange tiles in such an order so that the correct image is formed. This is also true of Rooms, except the object of the game here is to move the game's plucky hero from a starting point, to an exit represented by a door. Any tile that is occupied by Mr. X can be moved to an adjacent square, and he's free to move from tile to tile so long as there are no walls or obstructions in the way. Essentially each puzzle boils down to moving tiles about a grid with the intention of reaching an exit. Simple.

This fundamental objective is indeed easy to grasp, but Rooms quickly ramps up the difficulty with interesting twists to the formula. Telephones, for example, act as transportation devices, allowing Mr. X to travel freely between isolated tiles. Conversely, entering a wardrobe will switch the tile with that of another wardrobe-occupied tile, allowing the room to be changed without having to slide tiles manually. Candles can light explosives to clear obstructions, and fish bowls allow Mr. X to breathe in tiles that have been flooded with water. Each new mechanic is introduced just when you've become accustomed to the previous one, and the game always feels challenging as a result.

Structurally, the game is based around four mansions (although there are more that can be unlocked), each one housing a set number of rooms that act as each puzzle. The mansion map is laid out like a giant jigsaw board, and completing a level will unlock a corresponding jigsaw as a reward. Simply escaping a room successfully will unlock a blue jigsaw piece, while rearranging the tiles in the room to match the correct background will unlock a lovely gold piece. As well as individual puzzles, the mansions themselves have their own unique puzzle piece to collect (kind of like the star of a Mario world), which will subsequently unlock the next mansion. It's here the game introduces a style of play more commonly associated with adventure games, tasking the player with collecting certain items and using them in the right place to progress.

From my experience, a good puzzle game makes the player feel clever. It challenges and satisfies in equal quantities, and rarely feels frustrating. Rooms: The Main Building does all of this, and is genuinely addictive as a result. For those that really enjoy the concept, and think that they could create even more challenging puzzles than the developer, Hudson has been kind enough to furnish the game with its own room editor. Here, players can mix and match telephones, wardrobes and ladders to create their own puzzles, which can then be shared with a friend. Although I suspect that very few will make use of the feature, it's nice that the option is there.

The puzzling is certainly solid, but Rooms: The Main Building really lets itself down in the presentation department. Take a look at the screenshots that accompany this review; hideous, aren't they? Each environment is painted with a medley of browns, creating a dull, lifeless atmosphere. Everything is incredibly small too, with tiny pixelated models that just don't look coherent without squinting. It's a brown, blurry mess, and without a doubt the game's biggest shortcoming.

Rooms' bland and blurry visuals will do little to attract potential players. Its flaws will likely put off all but the hardiest of puzzle fans, but ultimately this is the exact audience the game was designed for. Rooms: The Main Building is certainly an interesting addition to the genre, and while the DS already plays host to a wide range fantastic puzzle titles, it offers something different enough to warrant a look.