When vectoring screenshots (especially those of low resolutions), I’d avoid doing shots with characters far away (ex: the girl). Unless you know how to work around them (detail them, fixing awkward body features, etc), I wouldn’t bother. In the animation they look awesome, but as a still frame, well… They require quite more work.

I wished you had put more into the lighting (make it more dramatic or something), or even put some texture work and special effects in it. The lighting looks flat overall. It’s just not that appealing.

This is a dynamic scene, meaning there is movement. Why not try and play with the motion blur where is need it? I’m sure, if done right, you could have had something more interesting, even with the lack of detail in the characters.

Vector wise, the structure of the characters looks fine. However, the eyes look quite bad especially the girl’s eyes.

In all, I’m glad to see a wallpaper of a series different from the regulars. Keep it up.