Alright <---art student for 2 years heres what I think. Too 2d no depth in it unless you were going for a heavily outlined 2d cartoony look. If not then you should really shade it, but first trace it incase the shading doesn't look the way you wanted to. Work from the top left to the bottom right and pick a single direction for the light source. If you wanted it to look this way then congratz it looks great.