At first I have to say your picture is awesome O.o
But now to the facts: You really make me feel the distance in this picture with the castle in the back and the trees which are fading away more and more. Furthermore the stucture of the foreground in very detailed, especially the flowers, the grass and the trees and the colours you chose are in perfect harmony with the theme of your picture. Now to the unicorn. It has the right anatomy and it makes the picture moving because of the tail.^^ I the landscape seems a little bit could, but also like a paradies everyone wants to visit. And with the unicorn it has a touch of magic. One only thing I could decry is the pink light. I think it's a little bit too bright and striking.
At the end you did your work very very well EPIC!!!