5 - A lot of potential here in my opinion. Criticism; I would like to have seen a better/stricter use of the rule(s), not only for the Challenge, but as a portrait, but I am no 'expert' on the Rule of Thirds. I think you have captured character fairly well but I see more potential - tighter cropping perhaps, excluding the 'shirt', even a selective desaturation maybe. The color in the hair, and the movement is good, and while the contrast of that color against the shirt is bolder, the shirt is 'competing' with the child - for a portrait anyway, in my opinion. Eyes maybe opened a tiny bit more, but 'as is', as I said, you have character here, the smile seems 'natural' (not forced) too. Not sure on the frame. Background is nice, although more 'level' or, alternately more 'diagonal', may have made this a better shot in my opinion.
This kid is great. Great expression! The placement alone the left 1/3 line is very nice. Light on the face seems to be about 45 front lighting and creates some nice shadows. Only thing is he had to squint.