Ooh I haven't seen an Ef wallpaper in a while.
Since I've got some time right now here's my comment:
Comment on the character - Nice vectoring!It's smooth and simple which is good. However, I find that the original scan
has much more colors compared to your vector. It kinda looks like you used Blending Mode > Color Adjustment > More
Cyan on your overall vector which made it lack a tint of red. Just compare the scan to your vector especially the eyes
and the uniform. So I think you might want to work on that. If you're thinking that it might not blend well with the BG,
there are other ways to blend character without using Blending Mode > Color Adjustment > More Cyan and since it
looks sunny, I think richer colors would go for it. Just because blue dominates the whole wallpaper doesn't mean that
you need to made a blue-ish adjustment to the character too.
angel already mentions that textless version is better and I have to agree. You can submit a text version as an
alternative version anyway.
The overall BG is too simple. Clouds shouldn't be in just one place coz yours looks like crumped in a horizontal manner.
I think they need to be dispersed.
Here are a few cloud BG to look at on how they are oriented.
My Secret Garden by shinta
.:Dreaming in Blue:. by Osiris
A Happy and Carefree day! by srsn
?~Taisetsu Na Hito~ by srsn
Hope that helps.