Hot from the successes of Breakfest and Speedfest, Arctica has produced Circles, something slightly simpler, more of a casual game, relying on your reaction time, in various game modes, to tap on expanding and contracting circles before they disappear. Like the best arcade games, this quickly gets hard - perfect for a bus stop challenge?

Here's Circles in action:

Acrtica's usual huge-fonted main menu system...

Five game modes introduce welcome variety. In order from the top: 'Basic', you have to tap on circles before they disappear; 'Reaction', you have to be very fast to tap on individual circles that only appear for a second; 'Cloud', ignore the circles of one colour and just tap on the other; 'Order', where circles have to be popped in the order in which they appear; and 'Duel', where the screen gets split in two and players battle (taking it turns) to get their 'reaction' circles popped - out perform and your health bar gets eaten up by your opponent's.

The basic game field, note that some circles pop up in the corners, these make the game quite hard since that's where your thumbs will typically rest, obscuring the rapidly growing disc!

Help screens are available for each game mode, rather oddly in the same huge font - but hey, great if you're short sighted?

Several stats screens are available, including this one, showing your popping accuracy over all the levels in a game (I stopped at level 27 to write this review, though things were getting very quick!)...

This isn't in the same graphical league as Arctica's previous titles, but it's competent and challenging and still worth grabbing if you like reaction-based titles....

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