It's actually kinda old, but I was thinking about going back to it. I'd like to know what should be fixed before I go for another try, so I'm posting it here, obviously.
Hmm, well the head is too small, the proportions are a little hard too tell, so don't ask me that. Add a bit more meat to the arms and legs to give him a little bit of bulk and muscle. Apart fromt hat it's yours to alter, since the only thing I would suggest would be the overall look of him like a change in hairstyle.
Okay this one I see some flaws this time. The neck is a little too long, the arms are showing almost no muscles at all and everything else looks fine. Overall, this one looks good.
The neck is only a tiny bit to skinny, and the head is a tiny bit to small. besides that though, its all good ^_^
if you draw the head a bit bigger and the neck a little thicker it would improve it a lot. Overall it is a good drawing.