First glance I see random noisy dithering, lack of contrast, and no shading in a lot of places. The shoes are out of perspective with any floor he might be standing on, his left hand is missing anything to define it from the background, or even define it as anything other than a yellow blob, and his right hand is missing completely. The comb looks like a green giraffe, his afro looks like a marble counter, and he seems to be sticking his tongue out at me from under a milk moustache. The initial lines are pretty good, but beyond that there is no shading to define form except on the pants where the contrast needs to be brought up. One mistake you haven't made is using retina-burning colors, so I'll commend you on your color choice. It could be better, but it's one of the better aspects of the piece at the moment. I see significant improvement from your last blockman, but this still has a lot that could be improved. Good luck!
Note: I'm sorry if this came off as harsh, but I was just writing what I saw.