The principal redeeming factor is the three adults in the cast, of which more anon.
Based on a true story (yawn!) its central character, played by Asa Butterfield (the titular lead in Scorsese's excellent 'Hugo' of 2011), is the teenage mathematical prodigy son of a widowed mother. Having been present as a child when his father is violently killed, he's become emotionally withdrawn to all, has inept social skills - but especially cold, unresponsive and, frankly, rude to his suffering, caring and loving mother. Sally Hawkins is astonishing as the latter. We see her trying to put on a cheerful face while trying to mask the worrying turmoil she holds underneath. Her sympathetic performance really tugged my heartstrings every time she appeared.
The story takes the son from being tutored as a child in advanced maths by the bear-like and muscular dystrophic Rafe Spall (son of Timothy S.), jumping some years to his attempting to compete for a place in an International Mathematics Olympiad at Cambridge University. He's taken with co-competitors to train in Taipei with the Chinese team (cue music with an Oriental 'tinge') where his withdrawn mien doesn't make him any more popular. His team's mentor and guide for this Far-East visit is the irrepressible Eddie Marsan, all energy and efficiency - and yet another 'bear'!
Apart from the music (there are even snatches of three songs, would you believe it!) I thought the arc of events was very much what we've seen a number of times before and, notwithstanding that it's based on true events, it's all capped by a feelgood ending which struck me as more convenient than convincing.
There were also, in my view, rather too many flashbacks to the character as a child responding to the affection of his shortly-to-die father.
We've seen Sally Hawkins recently in Woody Allen's terrific 'Blue Jasmine' as well as in Mike Leigh's superb 'Happy-Go-Lucky' (where her weird and disturbingly serious driving instructor was the same Eddie Marsan as here, though in this film the two only have one brief scene together).
Director Morgan Matthews, whose first feature as director this appears to be, has assembled a flawless cast and it's the three adult actors who hold the film together, being a total pleasure to watch. More's the pity, then, that the film itself was so marred in certain respects - though, of course, that may be just me..........................6.