The idea behind Jewels is familiar, of course - switch pairs of jewels to create lines of three or more, at which point they disappear and more jewels drop in from the top of the grid. In the process, this effectively creates a whole new configuration to study - play the game well and you can line things up in the right order so that your possible future options are maximised.

Here's Jewels in action:

Written in Qt, Jewels is certainly colourful, though if I were picky, I'd point out that the toolbar button borders seem to vanish against the screen edges. OK, ok, so that's really, really picky... 

I loved the way the backgrounds change every now and then, giving the game a subtly different feel. At some point the timer will run out (in normal mode) or you'll run out of possible moves (in relax mode), in which case it's time to save your high score.

One subtlety that's perhaps a little too subtle is the timer in 'normal' mode - a shade effect in the background starts advancing to the bottom of the screen - match 3 or more in a row and the shade relents, moving back up a notch; take too long and the shade continues downwards. Your time runs out when it hits the very bottom. Although you get used to watching for the shade, I'd suggest either starting it from the very top, to make the effect more obvious, or including a digital timer as well, down in the status bar.

As with most puzzles of this kind, there's more here than meets the eye. Casual players will just take easy matches, advanced players will plan the order in which they match jewels so as the maximise their chances later on, or to shift awkward jewels by arranging matches beneath them.

You can buy Jewels for £1 here in the Nokia Store.