Platform titles don't often transfer well to the iPad's touchscreen – the precision needed for exacting jumps is hard to replicate with the sometimes unresponsive tactile controls. Thankfully, charming indie title Thomas Was Alone (iPad, Bossa, £5.99) manages to get the interaction between avatar and player spot on.

Narrated with a wry tone by Danny Wallace, it invites you to control a red rectangle, Thomas, as he becomes a self-aware artificial intelligence in a grey digital landscape. Some simple running and jumping follows, before the eponymous hero is joined by further quadrilaterals, including Chris, a grumpy, squat square, whose jumps are limited, and arrogant, tall, yellow John, a superb manoeuvrer. More are to follow, with ever varied abilities. You must combine the skills of the four-sided, two-dimensional travellers so that they leap about the levels and reach the end points together.

It starts simply, but becomes impressively challenging as the, at first, antagonistic shapes must help the differently abled to reach seemingly impossible destinations. The sophisticated combination of platforming and puzzling makes for a gripping adventure.