Funnily enough, I have been dabbling at rebuilding this to work with this project: https://github.com/ludovic111/horizon
The only thing about rewriting it in rust is that no other mods will work with this and the thing that got me really excited about building this is using Create Aeronautics with it.
i think it should work with a free version of minecraft. maybe not even calling it minecraft.
standalone game that can only be played on the server. everyone gets a random stating position. if you start as a group you spawn together. always as far away from others as possible. so that you have to make an effort to find other players colonies.