Really nice design, although the shortening of her legs looks a little odd (it's like, when you got past her waist you choked or thought you were making a chibi). Her hair makes her look like Mangetsu from Bleach or "Biligual-multiple-personalities girl" from Sayonara Zetsubo Sensei. I'm not saying this is a bad thing, it's just that I've seen this hairstyle a lot lately.
The style difference is marginal. Perhaps an additional layer added to the background or foreground would help add some more depth and sense of scale to this piece. Perhaps the Earth or a comet to reinforce the stars?