Not bad, I do think that the feet on the top right and the shadow on the left hand side could be 'cloned' out.. They distract you (especially the feet) from the skater..
Also the little shade of a tree(?) at the bottom right... if you could've gotten the skater to move just a little bit more.. so his shadow would be separate from the tree..
I know these are little niggles and so on - the shot I think is good (and especially if you only had that 50mm lens with you!). So don't take this as huge critique, just few things I thought would make it a 'better' picture.