The first thing that catches the attention are the colors. I think artworks look and feel very expressive with colors. And you have a very lovely color palette. Rich and Diverse
The character looks very pretty but she has a mysterious and self-confident, and I really like that. Speaking of the character one of best thing about her in my opinion are her lips and eyes. They look absolutely majestic. I can tell u put a very decent about of time and effort on this character.
You mentioned that this is a new kind of art style you have tried but I am amazed how you nailed it in your first try. It almost feels like you are use to painting like this and you feel comfortable with it.
Now there is one thing I would like to add, it is a great painting for a portrait but I think for a mascot it is too damn detailed. I hope you are not offended by this but I think that the mascot is more towards logo design kind of a thing.
Otherwise, this artwork itself is great, no doubt. I love it, your technique and how you composed it.
I hope I was not rude and that this critique was actually useful to you