Five years ago Prachya Pinkaew, a rising force in Thai cinema, forced new energy into the martial arts film with his clamorous, violent, distinctly uncomfortable-looking Ong Bak.

Now, Prachya returns with another pleasingly original film - here the kicky, punchy heroine has autism - and, once again, when planks make contact with skulls, the owners of those skulls look properly bashed-up.

There is, to be sure, a kind of elegance to Prachya's choreography, but it is the elegance of collapsing buildings and felled trees. Watch as Zen (Yanin Vismistananda), who developed her talents by watching TV, beats up a cadre of hooligans on a series of parallel ledges and marvel that Donkey Kong had such a lasting influence on popular culture.

Chocolate, which treats the condition of autism with surprising maturity, includes a bountiful selection of documentaries. It comes as no surprise to learn that more than a few bones were broken making this exhilarating flick.

Directed by Prachya Pinkaew. Starring Yanin Vismistananda, Hiroshi Abe, Pongpat Wachirabunjong 18 cert ****