how can you wear a head not in-game?
by the way, I like your mapping and design overall,
for my taste I think you should do more shading in your heads,
maybe a tone of white to give focus or some red on cheeks and nose.
Your eyes are just not detailed enough to get attention, work a bit more on that.
You do a good work, you can improve a lot yet,
keep doing what you wish with art and you can eventually get better at.