Almost There!

i'd make some adjustments to the various line widths of your elements - especially the girl. the lines themselves need to have a little more personality through tapering, different widths, etc.

i see you've started to do this, but i'd think about taking it a step further and really committing to your linework to give it a little more life and character.

it looks like a good concept, but you need to adjust/think more about the final art. the background gradient does not help much

I like it. Add more details to the face