>>1563228Circled in RED are minor things I see. I suggest that you go through the whole image and check your line consistencies - they are neither parallel nor consistent in thickness. Once those are fixed, this will look really good.
You could also play around with gradients for the shadow shapes - just make sure you point your gradients as lighter going from light source to darker, away form the light source, but it will be fine as it is, too...
