I see that this post is 3 months old and I'm not sure if you still want/need this feedback but here it goes.
First of all, this is a good start, you definitely have talent and probably experience drawing from what I can see.
Ok, let's begin:
One thing you should consider, as you plan on making this character for a game, is the size of the sprite and how many animations you will make. As a begginner, it's usually pretty hard to start with a big sprite like that. I'd recommend you tried smaller sizes (such as 64x64, 32x32, 16x16).
BUT
If you still want to continue with this particular one, the first tip that I can give you is to decide a light source direction. When you do that, you should cast all shadows from it. As it is right now, there are some inconsistencies: the top-left seems to be the source but there are spots from the right on the arms and the hair that are getting some highlights. The neck part should also be darker on the right.
I hope that makes sense. In 3 months you could probably have already improved a lot so I won't get too in-depth.
Good luck!