Hey! Thanks a lot :)
Unfortunatly, I'm totally unvailable for now to do commissions. A lot of people ask me for extra-content and that's not possible for me right now.
Still, I'm of course totally ok to let other artists work on extra-content, so if you want to commissions other pixel artists, that's of course ok for me!
I've even made a list of pixel artists I recommand (since I personnaly know them and have already worked with them) : https://twitter.com/i/lists/1348921662146830339/members
Also here is a website very useful to find pixel artists:
https://pixelartists.cat/lists/
Hope it'll help you :D Good luck for your project!