hello there!
I like the idea of the composition! My critique would be about the colors of the skin, which are too much desaturated, especially in this kind of lightning. Heat them up, put some reds and yellows here and there. Also, take a look at the anatomy, the muscles are really popping out, but the type of body does not match really.
Sorry if I seem to be too harsh, but I hope it helps. Keep on!!
