I don't understand the intent of your aesthetic. What are you trying to convey to the viewer - not just with this illustration, but with the entire style? I get the idea that this is supposed to be a pretty rough-and-tumble guy, but beyond that, I can't tell how much of the way he looks is a result of intent, and how much of it is a result of gaps in understanding of color, structure, and many of the other tools we use to communicate ideas to the viewer.
Who are your favorite illustrators? What do you like about their work? It's difficult to critique this in comparison to other pieces I've come across, because you can usually tell what aesthetic qualities a person values, and build a dialogue on that. I can't really tell here. I can't tell if the long faces are on purpose or on accident, or if the sallow colors are intentional, or if you highlighted everything with white (washing the illustration out further) on purpose. I can't tell if the character's face lacks structure on purpose.
Some of your other illustrations also seem to have this problem; you attempt to render things in 3D space, but the structure of your subjects becomes very confusing when it reads as 'three-dimensional' - the structure isn't something that works in 3D, because they aren't functional structures. >This picture< is one of the clearest examples in your gallery; you squared off his mouth and jaw in a way that isn't great in 2D, but at least reads adequately - but in 3D, you really come to understand that his top and bottom row of teeth are, in fact, squared off at right angles in the mouth, which is... pretty bizarre for a humanoid, but not pushed enough to look like an intentional exaggeration. It becomes an >Uncanny Valley< problem.
I am sincerely sorry if the critique seems rough. I've been wondering how to best get this across; I think you have a unique message, and I'm glad you're sharing it with us. I'm glad you engage in the kind of forward-thinking that allows you to redesign and mature characters. But - as a random viewer - I'm concerned that your message is getting lost in a sea of aesthetic confusion. I don't really like to tell people, 'study from life!', yada yada blah etc., but I think it could be really helpful here. Not because you need to be less of a cartoonist, but because a fresh perspective on the features you're abstracting in your illustrations could be very helpful.
Best of luck.