Thanks for references! I initially considered bevy for this but I was a bit scared it was not mature enough. How do you find it now?

Really depends: In some areas it is quite advanced (rendering) and in others it is lacking / underdeveloped (editors / tooling). But there is an incredible amount of progress and also churn in keeping up with that.

https://thisweekinbevy.com/ https://bevy.org/news/