I'm glad the feedback was helpful!
As for the options menu, I think it fits the game's overall style. It's definitely simpler than the rest of the UI, but I don't see that as a bad thing. The colors match the game's aesthetic, and I think it's clean, intuitive, and easy to use.
Personally, I wouldn't spend too much time redesigning it. I think it's already in a really good place, and I'd focus more on polishing the gameplay and adding the missing features.