I love the colours! They're so bright and saturated and it really pays off. But the perspective could be better, I feel that there isn't much of a sense of height. The trees in the background, the ground below the cliff, the guy and the dragon, there's not much in between all of these things. In my opinion, the solution would be to enlarge the canvas and show more of the background and plan how it's going to look in a thumbnail before doing anything else so that you have more freedom to exaggerate and accurately pose everything in the piece. Other than that, this picture is really pleasing to look at. Well done!