The sense of perspective and foreshortening in this illustration are wonderful and really make the viewer feel like they are truly up high and looking down. It has a real sense of distance and scale.
The character, the glowing door, the rustic sense of age in the scene, the light beams, and the general atmosphere also work well to create a sense of implicit story and curiosity.
It makes me wonder what is going on and what the world is like.
I'd say you did a great job!
It reminds me of the kind of professional-grade concept art I used to see back when I worked at a AAA game company as a programmer whenever I saw work from the art department.
The artists there were amazing and this piece has the same hallmarks of great understanding of fundamentals and the principles of artistic composition and layout!
If this is original work (not traced) then I'd say you have the same potential and capability.