This is a must-see and one of the best documentaries - and films - of this year.

This is one of the few movies I've ever seen where the whole audience broke into spontaneous, loud applause a third of the way in.

The movie turns out to be a little better than the average. Starting from a romantic formula often seen in the cinema, it ends in the most predictable (and somewhat bland) way.

The joyful confection is coated in a sparkly gloss, bright enough to gleam from the darkest, most cynical corners.