I've never heard of the series, but the picture looks great. Good work with the shading, lighting effect, and vibrant colors. The way she is running, however, looks a little awkward; her knees are nearly touching each other and if she was actually running, her other leg would be more forward than it is to take the next step (though if her leg was like this, I don't think it would look as good).
I also like what you did with the background. It appears to be transitioning to day where she is running while behind her, it is night (I don't really understand the purple zig zag though). Still, very good job on this picture. My final comment is this: are those arms growing out of the cat's ears?