The eyes are a bit too high, are you using guidelines? If not you should they help get the placement of facial features, going along with that the nose is a bit too large not sure about how to suggest improvement there.
I feel that the hair is a bit off maybe do another pre sketch before jumping in to lineart and coloring, just make sure everything is the way you want before jumping in to coloring, also the hair should be a lighter color of green but as far as improvements that's all I can suggest!
I really love your unique style though and I hope you'll keep going at it!
Thanks for the input! Believe it or not, this was the first "reference free" image of a human I've done in a while, and it's also the first painting of a human I've done in a while where I skipped the pencil entirely. Again, I'm a lot happier with it than I am with just about everything I've done the old fashioned way except my Mama entry.
Still, I see what you mean, especially with the eyes and the hair color. I suspect the hair color may be wishful thinking on my part; I don't particular care for the canon shade of green.
I'm going to try to find a way to incorporate guidelines into these "no pencil" pantings on your suggestion without losing them underneath the first layer of paint. Thank you.