I actually quite like the hair colors, and the sharp nose isn't so bad, the thing that strikes me most is the dark outline around the shirt that isn't anywhere else on the piece.  I'd like to see the entire thing outlined like that, especially against this grey background.  It looks good on white, but the edges get lost here.  

The style is so neat though!  I'd love to see you work with it more.

 The pointy nose, the mouth (the disconnected pixel on the left side), and the hair colours are what I don't really like about this piece. Unless your noise is really this pointy in real life, I suggest you'd change that. It's pretty good otherwise, though. Still a lot better than my work :p

Although, it's pretty unique, and that's one thing I love about it.