Treasure World

Kids love collecting things, as anyone who's ever been embroiled in a Panini sticker-related dispute can testify. So it's no surprise the vast majority of videogames involve collecting things, whether that's coins or points or Pokemon or Enchanted Wizardweave Leggings of Maximum Fire Resistance.

Treasure World revolves entirely around the concept of collection. The twist is you don't pick up items as you explore the in-game environment - in fact, there's barely an in-game environment to explore. Instead, you gain new stuff by wandering around the real world with your DS in tow.

On hand to explain all this is a cheery professor type. He looks like what Dr Robotnik would have turned out like if he'd had a happier childhood. He's accompanied by the Wish Finder, a little robot character who is surely the lovechild of Clank and Nono (small robot you know). Their spaceship, Halley, has crashlanded in a moonlit garden, and naturally they need your help.

Your mission is to earn enough in-game currency - otherwise known as Stardust - to get Halley powered up again. In exchange for Stardust the professor type will give you in-game items, otherwise known as Treasures. These include items of clothing you can use to dress up the Wish Finder, such as t-shirts, baseball caps and ninja outfits. But there are also environmental objects to collect such as flowers, trees, mushrooms and cacti, plus a huge number of random items like teddy bears, hay bales, Easter eggs, four-leaf clovers and anal beads. Maybe not the last one.

Both Stardust and Treasures can be found by telling the Wish Finder to scan the skies for stars. In practice, you're telling the DS to scan the surrounding area for wi-fi signals. Each signal generates a unique star and each star yields a prize, which might be 10 units of Stardust or a lavender plant or a new pair of trousers and so on.

If you live in a built-up area you can pick up plenty of rewards without leaving your lounge, but it's really about exploring the world around you. Just set the Wish Finder to scan, pop the DS in your bag and go about your everyday business. The scan continues even with the handheld's lid closed, and a satisfying "Plink!" is emitted each time a new signal is discovered. (You can turn the volume down if you find this annoying or are at a funeral.)

This is where the fun starts. You might return from the corner shop to find you've picked up a prickly pear, a belly dancer's bra and a new kind of hedge, although you only went out for some fags. During a 30-minute expedition around magical South-East London (through the estate, down to the Harvester then back up past Tile Magic) I came across 103 new Treasures. (Plus 47 empty Stella cans, two abandoned sofas, four cross-looking gentlemen who probably ought to have been at school and one incidence of racist graffiti, but that's by the by.)

There's something stupidly pleasing about opening up the DS again to discover you've acquired a host of new Treasures. That applies even for grown-ups, though the novelty wears off a lot quicker than if you were nine. Still, the collection element of the game is innovative and works well. The problem is, there isn't that much to do with all the masses of stuff you acquire.