Yes I agree with Bianca, I'd like to see this saturated and with the feet in picture,, The bars in the background detract a little, they tend to make the overall image a little "busy",,, I'm surprised that the DOF isn't more defined with the 2.8 f stop.
Mind you, this is only MHO and the photo is wonderful, I know, I also am a grandfather,, lol,,,
I like the subject of the photo, it's very creative, but in my opinion, the lightning is not the best... Maybe you should darken the photo a bit so that the colours look more saturated and the image becomes more dramatic. As for composition I think it would be nice to see the boys' feet instead of the empty space above his hands... Maybe try another cropping? Just ideas, it's a cute picture anyway :-) Regards, Bianca