I can see you have put a lot of thought into his facial structure, and considering how different that is to the characters you've drawn previously, WELL DONE!! Not just for pulling it off rather well for a first attempt but getting your head round the differences!
The cheek bones are expressed quite well, and with a bit more shading I think you can bring it out even more I can see that you've tried to give a 3d perspective on his chin rather than just a straight square edge, perhaps that upper line of it can be slanted more upwards towards his left side just a little? In this angle, it gives the impression his chin is pointed. Also, just out of curiosity, what is that little square part just behind his ear?
Other than that, really well done and I'm so impressed and proud of you Bison is hard to draw and you did it first go. Really, really like how you did his hat OF COURSE!! -sorry couldn't help myself XD
Thank you so much!! ^^ Your review is helpful!! I did struggle with his chin; I wanted it to have sharp angles, but I see what you mean about the perspective. I think I ended up misinterpreting that little square behind his ear as part of his uniform when I was looking at different references... disregard that :l