If you don't mind giving up your solo cred, I'd be happy to team up. Sound and music is my specialty. You certainly have good sound already, that can't be denied, but I feel a little extra touch could bring some more life into it.
Viewing post in REDO! Dark Sci-fi metroidvania(DEMO)
As for sound effects, you could view my game AI: Wild & Free, available here on Itch. For music, I have a soundcloud and bandcamp. I'm actually currently working on a portfolio video atm, made up of content I've created over the past couple years. I can give you a link to that when it's finished, if you like. :)