This is a very warm and poetic film. It's about a mother's relationship with her autistic son and her insecurities regarding him, about his desire to run a marathon and how that relates to his relationship with his mother, and about how his running coach inadvertently helps to bring them together. It is one of the most touching films I have seen in many years.
Some people have compared it to Rain Man, but that's a comparison which does not stand. Firstly, the selfishness of Tom Cruise character and Dustin Hoffman's overacting make Rain Man a far less touching film because the characters are far less sympathetic. There is also the crucial difference in that in Rain Man the Tom Cruise character really had no interest in his autistic brother and did not wish to really have any type of relationship with him. In Marathon, however, the whole film is about the problems the mother has precisely because she wants to have a relationship with her son. It is this dilemma (the wanting to have a relationship and not really being able to do it) which makes the film so interesting and touching.
Furthermore the acting is very good, the cinematography is rich but not overdone, the music is very good at emphasising the poignancy of particular situations and the film has a wonderful pace: neither too fast nor too slow. All in all a very enjoyable film highly recommended for anyone who wants to smile, laugh, cry and generally feel happy.
