Work on your anatomy. His arm near the end looks lumpy and at the beginning it's too straight.
Can't really tell what that is in the background because of the bloom and blur, although I'm assuming it's a window.
You should make that clearer.
I don't like his eyes. I think there should be at least some white in them and that the blend in too much with his face.
Try using a radial gradient next time to give them depth.
you seem to have the basics down though. All you can do is improve from here
