LittleBigPlanet Karting is the offspring of two very distinctive parents. On the one hand you have Media Molecule's hand-stitched world of woolly platforming and Womble-esque construction, and on the other ModNation Racers, the previous kart racer from developer United Front Games. With ModNation's emphasis on customisation and user-created tracks, the combination is as obvious as it is inevitable.

Sadly, in splicing the two games together, something has been lost. The racing lacks ModNation's smarter innovations, while LittleBigPlanet's jumble-sale approach to structure loses the competitive element in a whimsical tangle that never knits together.

The front end is almost identical to the previous LittleBigPlanet games. You're in a bare cardboard pod with an array of craftwork worlds before you. Bizarrely, you can't just jump into a race and there are no cups or tournaments. Instead, progress comes from playing through a rather loose story mode, which unlocks the various planets and courses as you go.

As well as traditional circuit races, there are battle arenas, checkpoint rallies, top-down RC events, shoot-em-up boss battles and even a smattering of mini-games. After each event, you're sent back to the pod, from where you must go back into story mode to continue.

You can earn and construct dozens of karts, but they all handle exactly the same.

Somewhere in the middle of this tombola of stop-start gameplay modes, a decent multiplayer game is struggling to make itself known. You can play any of the story races co-operatively with up to four players, but to take part in a simple multiplayer race you first need to unlock the track's versus mode by beating it in story mode. It's never explained how co-operative racing is different to actual racing, and it's unclear why this separation was even necessary. By amputating competitive versions of the same track and locking them away, the game immediately makes racing against other players - the bread and butter of the karting sub-genre - an opaque chore.

Even after you've unlocked a track for online multiplayer, the game's structure pulls in the opposite direction to how racing games are supposed to work. Simply navigating to an event down the game's winding pathways is off-putting and with no tournament structure in place, you just wander from one event to another, voting on which one to play next.

The racing itself is sturdy enough to glue this cut-and-paste experience together, but it never quite hits the sweet spot. The karts themselves handle well, if a little heavily for such a frothy game, but wayward balancing and inconsistent track design mean that whizzing around is never quite as much fun as it should be.

Most of the design can still be traced back to Mario Kart. There are boost icons and weapon pick-ups, ramps and bounce pads. You can use Sackboy's grapple to swing across certain chasms, but that's about the only influence that LittleBigPlanet's gameplay has on the actual racing.

Weapons are the game's other big problem. There's a variation on ModNation's shield dynamic here, as any equipped weapon can be aimed backwards to ward off homing attacks. It's an imperfect system though, and where ModNation allowed you to build up a gauge for defending yourself, by making the player rely on collected weapons it's easy to use your weapon to shield against one attack only to be immediately hit by another.

"For all its snuggly overtones, LittleBigPlanet Karting never manages to stitch its two halves together convincingly."

The flying boxing glove is the best of the weapons, provided you're riding it and not being knocked out of its path.

The AI in the story mode - which you must play, remember - is just no fun to race against, often hammering you with one attack after another, each one capable of taking you from pole position to the back of the pack right at the finish line. Add in tracks that are infuriatingly fond of obstacles that cause instant death with the slightest touch and it's a recipe for frustration.

For all its snuggly overtones, LittleBigPlanet Karting never manages to stitch its two halves together convincingly. The irritations of the obligatory story events and the fussiness of the multiplayer structure combine to muffle the basic charms of the karting genre.

And that's a shame, as there are gems buried in amongst all this old cardboard and paper. The battle arenas are good fun, and the better race tracks are a real pleasure when you have human rivals to compete against. The weapon balancing is still awry, but at least when it's a flesh and blood racer catching you out it doesn't feel like the game itself is punking you.

The social features, inherited from LittleBigPlanet, are gracefully implemented, enabling you to swap, share and stalk your friends with ease. And, of course, there's that LittleBigPlanet patchwork aesthetic, still charming after all this time, with a visual style that you could almost reach out and touch. Stephen Fry also returns, indulging his Oliver Postgate fantasies with near-constant narration delivered in a voice as comforting and inviting as a warm, buttery, Sunday afternoon crumpet.

Also deserving praise: creating your own race tracks is far easier than putting together a level in the main LittleBigPlanet games, thanks to the intuitive tools borrowed from ModNation Racers. Simply steer a giant paint roller around the landscape, and your track fills in behind you. Shoulder buttons allow you to bend the course up and down as you go, and an auto-complete option means there's no fiddling around at the end. The only downside is that you can no longer ask the game to automatically decorate the track side in your chosen style - every object must be placed individually.

"A misshapen cardigan of a game, inviting warm affection but constantly struggling to earn it. "

You don't just have to create race tracks - as with LittleBigPlanet 2, you can create all sorts of games in the Creatinator.

Even if you don't want to create your own tracks, the community features are such that you can still seek out the best of the user-generated content to extend and enhance the core game. Or at least, you can if you've bought the game new. Karting comes with an online pass, and if you don't have one you can expect to pay an additional £7.99 to take advantage of all the online features. That means no multiplayer races, no uploading your creations and no sampling the work of others.

This isn't the only game to resort to such measures, of course, but it feels especially awkward here, in a game that has always lived or died by the engagement of its community. With the offline gameplay proving less than satisfactory, roping off the heart of the game behind a members only barrier is a disappointing development for a series that defines itself by its inclusive and generous nature.

The result is a misshapen cardigan of a game, inviting warm affection but constantly struggling to earn it. There are glimpses of a game worth loving tucked away in the folds of LittleBigPlanet Karting's chunky lop-sided weave, but it too often goes out of its way to bury those simple joys under fussy distractions and needless obstructions.