-Pokemon 20 Celebration- Celebi

Here's something I made a while ago celebrating the 20th anniversary of Pokemon. I never finished drawing for every month, but of the 3 (yes, only 3 months completed), this was by far the best out of them all. In fact, this may be one of my best digital drawings to date (which is especially impressive considering there is practically no layer system in Pokemon Art Academy besides the outline pen, which I only used as a guideline for myself in the process). No joke, this is one of my all-time favorite drawings I've ever made. Someday I will finish the rest of the celebration artwork. 
    
As I am proud of this work, I would like some critique perhaps? If anyone has any. I would like to improve from this (once I can achieve this level again XD)

Celebi belongs to GameFreak, Nintendo, The Pokemon Company