I find its way too dark and contrasty for my taste
The entire right side of the frame is a black blob on my monitor (uncalibrated work monitor, but still..)
I find the outside comes off as more of the subject than the the kid. His head is a bit low in the frame, which probably adds to the importance of the outside and also puts a bit too much space over his head.
Its a cute photo, and I'm sure its a nice moment captured, as he seems happy and having fun, but I dont think it makes it as a photograph.