You seem to have a solid grasp of facial anatomy and lighting. The color choices are bold; the neons in this piece remind me of '80s-styled work. Some of your other pieces have too much saturation for my taste but I think this one has a better balance of neon to normal. I appreciate that you put enough thought into this one to develop a write up for it, but I'm gonna let this crit be solely about the visuals.
The one thing in this illustration that I don't like much is the edge of the beard. The lighter skin tone at the edge gives me the impression that the skin is overlapping the hair, which just looks weird.