Some things to consider... And hopefully helpful...
The keyboard draws my attention away from your hard work. Download a fade background. They are all over the internet. Thin your paint down a bit. It is visibly thick. start with a 1:1 ratio of paint to water and go thinner from there for shading purposes. Also, use diffused lighting for your photography, it will help. CMON has an entire section of articles devoted to photography, read them all.
I really like the colors. He is cool! I can't believe this is not getting a higher score. Some voters are just hung up on wanting everything to be dark and dreary.