The iPod wasn't built for gaming. That much is obvious. The iconic touch wheel at its centre may be elegant, but it's never going to be much of a controller. For Peggle, however, lack of control isn't an obstruction to the game. It is the game.

An enormously popular web-based title from PopCap's casual stable, Peggle is a version of the equally popular Japanese game pachinko. Both consist of a falling ball, a set of pegs for it to bounce off and an incongruous riot of noise and colour to accompany the otherwise unmoving spectacle of uncontrolled descent.

To be fair, some skill is involved in Peggle. As the pegs thin out, you'll need to be able to roughly judge trajectories, consider rebounds and calculate angles, but these moments take up the least time and give, by and large, the least pleasure. Really, Peggle is all about randomness, and watching your ball cascade by sheer fluke onto the right peg is every bit as satisfying as pulling off a skilful shot.

Indeed, your input is limited to an opening moment. You control a turret at the top of the screen, and at the bottom is a lidless drum that sweeps rhythmically back and forth. Between turret and drum is an arrangement of pegs and tiles varying in complexity from simple grids to elaborate designs following the contours of the zany, beautifully-drawn backdrops.

In the level entitled 'I Heart Flowers', for instance, the backdrop is a row of three tulips and the tiles follow the outline of the stalks and petals, while the pegs are scattered more or less randomly around them.

As you may have guessed by now, you aim the turret left and right by running your thumb around the touchpad, while a perforated line pours from the end, indicating the course the ball will take when you fire it.

The object of each level is to remove all the orange pegs from the screen. The standard blue pegs get you points, and more crucially give you something to bounce off, but removing them doesn't get you any closer to victory.

Once you've pressed the button at the centre of your touchpad and launched the ball into the arrangement of pegs and tiles, there's nothing more to do but hope it hits a lot of objects and, with luck, finds its way into the drum at the bottom of the screen, giving you another attempt.

Cocky upstarts may come to Peggle thinking they can guide the ball to success, but after a couple of bounces chaos reigns, and only the haziest bet-hedging is actually possible.

The best way to do hedge your bets though is aiming for power-ups. Purple pegs get you points-boosts, while green ones bestow advantages such as extra balls or an extended line-of-trajectory.

Like pinball, the bonuses can be doubled or tripled if you happen to hit more than one purple in a single shot or rebound into one from a long distance. With very little encouragement, the game can end up ladling on rewards like some dream confectioner shovelling sweets into your hands. The points escalate so furiously that by the end of a good level you might stumble away with a six-figure score - more points than you can spend in a lifetime � while rainbows and stars celebrate your success.

In terms of structure, there's a standard Adventure mode, in which you make your way through 55 levels, and once you've completed these � and only then � a Challenge mode unlocks in which you have to complete 75 increasingly difficult specific tasks. Completing the single player game is likely to take you months.

Add to this a two player versus mode, in which you can either play against a human opponent or against the computer, and Peggle's longevity approaches infinite.

Visually, it also looks just as good on our iPod nano's colour screen as it does on a PC monitor, and all of the original's exuberant character is reproduced in fine, crisp detail. Looks were always a part of Peggle's charm, and they aren't diminished on the small screen.

So, although it started life as a mere web-based bagatelle, Peggle became one of the most talked about games of 2007, as well as a perfect match for the iPod's distinctive interface. The iPod may not have been made for gaming, but with Peggle, gaming's managed to overcome Apple's oversight.