Okay I've never done this before, but I'm going to try and do a critique now, bare with me.
Your shading and lineart technique are great and look very good. The anatomy is okay but there are some things that could be better~
At first sight, I think he looks really good but when you take a closer look, I think that his cheekbone looks pretty weird. The lines go inwards so it looks like hes got a dent in his cheek? His neck is also too long in comparison with his head. And his shoulders should be slightly going downwards instead of upwards.
I really like the headphones, only they look like they're flat on his head. Maybe try looking up pictures of it and make it look a bit rounder.
I don't really know what to say about impact -silly me-. But I really like this drawing, it's very cute, and I definatly think you should draw more humans! c: