So I come here and I'm cleaning up some spam comments and I realize that this wallpaper is five kinds of sexy and all green. This needs to be commented on. So, in the process of overwhelming you even more because I'm random like that, I bring to you another huge comment! Run for the hills!
So, first off I'm really glad that you chose to work with such an image. It's always nice to see a series, or an artist get more attention when they are virtually untouched. Especially with such a powerful piece like this. As for the character itself, you did a great job vectoring and touching up with the additions to the moon itself and the girl looks fantastic. I especially love the choice of using different hues of Green you worked with, as well as the pattern on her skirt. It's so peaceful and relaxing to look at her.
As for the background and the moon itself, I absolutely adore the fact that you kept it so minimalistic. To me, the night is about tranquility and bliss. Especially when gazing at the stars and the moon. Everything is so still and so vast with beauty, that it's so easy to get lost in a sea of elegance. This wallpaper shares that similarity and then some. By keeping the background with the minimal amount of stars, not only do you create icon space, you more importantly allow the viewer to relax and appreciate the girl and the moon even more so, which is huge for a wallpaper like this. I find it very soothing, and if it had been saturated with different things it could of easily lost that element. As for the moon, I love how you added that crazy bit of design idea from the scan you linked, yet at the same time kept it very clean and simple. Simple, clean, and to the point while being visually pleasing.
Well, I won't deny it, this wallpaper is super effective. I am very sleepy, so that's what I'm going to do right now is sleep and have some green dreams with a girl on the moon and a giant round sheep jumping over them.