As an individual piece, this is very pretty, but if it's a game mockup then the traversable environment needs to be easily distinguished from the background and foreground elements.  Right now, the only thing that's easily separated like that is the character.  Still, beautiful.

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 Creative UI, but the health bar isn't clearly readable at a glance.  Something like health is extremely important, and you need to be able to look at it on the fly and get a clear reading instantly, because you're paying attention to many other things.  If you're going to keep this UI, make the sword much larger and thicker, and more different in color than the mana orb, so it's clearly readable.  Red is a pretty universal health color, since it's so easy to see.