If ever a game was made for iPod, it's Zuma. After all, the basic premise involves a frog sat at the centre of the screen, rotating 360 degrees to spit coloured balls out of his mouth. It's absolutely perfect for the iPod's scroll-wheel, which explains why Zuma is one of the most satisfying iPod launch games to play.

But hold up: let's take a step back for those who've never Zuma-d before. You play the aforementioned frog, and your task is to spit those balls at long lines of other coloured balls that roll onto the screen, creating chains of three or more of the same colour to make them disappear. Clear the screen and you're onto the next level, but if the balls reach the golden skulls at the end of their lines, you lose.

Zuma is thus a distillation of numerous casual puzzle games, so it's no surprise that it's been a big success both on the Web and as a mobile game. See, it takes about two seconds to grasp the basic concept and start clearing the balls, but there's bags of depth beyond that.

There's the combos, for example. Whenever you clear a batch of coloured balls, the ones next to them slide back to rejoin the chain. If that results in another link of three or more same-coloured balls, they disappear too, and you score a combo.

Your frog shows the ball he's about to spit, but also the one after that, and you can swap them by pressing the Rewind or Skip buttons on your iPod. Careful juggling lets you line up combos to score more points. Meanwhile, you can also shoot coins for extra points.

There are power-up balls too that, if triggered by making them disappear, give benefits. The Accuracy ball sharpens your aim and lets you fire more quickly, while the Backwards ball makes the whole line roll back, giving you more time to complete the level. The Bomb ball explodes, destroying balls in its vicinity, and the Slowdown ball slows the line's progress.

It's all these features together that make Zuma a superb puzzle game, as you'll quickly graduate to the level where you're lining up combos and scanning the screen for coins and power-up balls to send your score rocketing. There's also plenty of depth, with more than a dozen levels to work through.

Like all iPod games, you can choose to have your own songs tootling along whilst you're playing, with the game sound effects overlaid on top. If you opt for Zuma's own music, you get a mix of suitably tribal-lite themes. Although occasionally veering into panpipe hippy-compilation territory, these do match the game fairly well. The clacking ball sound effects are fitting too.

Alongside Mini Golf, Zuma shows off the potential of iPod gaming to its fullest. It's quick to get into, much slower to master, and crucially it works well with the device's unorthodox gaming controls. Marvellous stuff.