I like what you're trying to do here, plenty of things going on and plenty of characters to show for it. But I have to stop you right there and say that books are meant to look a little more plain than this.
Books aren't known for their overwhelming visuals - people don't want to see a million and one different pictures, they just want a vague idea of what's in there. This kind of style is more suited to movies rather than written works.
However as far as what you've got here goes it's pretty damn amazing. I'm having a hard time figuring out if the characters here were photographed and digitally edited or drawn completely off by scratch. Either way it works.
Sort of, anyway.
You've got a bit too much contrast between top and bottom. It makes me think I'm looking at two different things at once rather than a single product; the art styles are simply too different.
I hope this is clear enough for you. It's a good start!
thanks you for the critique on the picture.
I did upload this, to let people imagine what the cover would looks like, and the chracters in reality.
I agree, it looks too much like a movie poster.
Those characters where manipulated from other real photo's, since i sux at drawing realism things.
For the contrast, i used this picture as reference, so it could be a little of, since i based it on this:[link]
mabye i will improve it in future, but i keep the tips in mind.