Alright, I saturated the colours, added a light red outline, extended the glasses and added shadows to it to give it more depth, and tweeted a few minor details. I've always had trouble finding a good art style, but I think I'll be getting somewhere this time.
EDIT:
I changed the colours a bit more and added a different expression, along with a few other touches, also
Here's a banner thing, the tiny sprite is the original design I made. (Ignore the stretched pixels to the left of him, I dun goofed)