Not liking the smudging on the left arm there. The signature needs a bit more. It is all in all a bit plain right now. The bubble C4D is scattered all over the place, which ruins the depth. Not sure what the bottom right white spot is, but it seems like it shouldn't be there. Also, the light source is shining on the back of his neck, when it is night time.

Keep working on it. I know you said it was a new style for you, which can always be tough to work out at first.