At a young age Nathan Ellis (Asa Butterfield) was diagnosed with autism as he didn't communicate well with others but had an ability to understand maths and numbers few have. But also at a young age he lost his father, a traumatic event which left his mother Julie (Sally Hawkins) desperately trying to raise him single handedly but struggling due to his OCD and unintentionally demanding ways. But it is through maths that Nathan is introduced to Martin Humphreys (Rafe Spall), a grumpy teacher suffering from multiple sclerosis who mentors Nathan to try out for the International Mathematics Olympiad.
Whilst it is easy to categorize "X+Y" as simply a drama what I like about it is beyond that it is a movie of all kinds of everything which works together. As such on the surface level we have this drama about Nathan; a young socially awkward, autistic teenager who is OCD when it comes to things in his life but who is also gifted when it comes to maths. But it is so much more because whilst we watch Nathan thrown in to a world where he has to communicate with others, make friends and experience feelings which make him come out of his shell we also get to appreciate Julie's life as she is at the end of her tether caring for her son who doesn't show her any sort of affection. We also have Martin's story and his own battle with illness which he deals with by approaching life in a bitter but comically cynical manner. These three character's stories and the events in them make "X+Y" a simply enjoyable drama, the sort of which you finish and know you will watch again one day.
But part of the reason for "X+Y" being so effective is the main three characters and what the actors bring to them. Asa Butterfield does this marvellous job of making Nathan anxious during those moments of social awkwardness to the point his distress whilst controlled is tangible. He also does a great job of making Nathan hard work for others as he is very literal when it comes to what people say but he doesn't over play this side of it to be too focused upon. Then you have Sally Hawkins who brings out that heart wrenching mix of love and pain she suffers daily as she cares for Nathan but gets nothing back from him. But on top of that you have the equally brilliant Rafe Spall who masters the humorous cynicism of his character in a way which whilst providing laughs never feels like it is being played for laughs.
What this all boils down to is that "X+Y" is simply a really enjoyable movie which keeps you watching from beginning to end and provides you with a bit of everything from love and pain to cynicism and humour. And as I said this is one of those movies which once it is over you know that at some point you are going to watch it again.