Hey I wanted to give some suggestions on how to improve the aesthetics of some of the planets.
Neumann V: I personally feel the generation of the satellite would look more interesting if It wasn't just a bunch of perfectly spaced squares. Maybe have them be more roughly shaped metal island chunks. I understand its an artificial surface but having the satellite be broken in nearly perfect squares is kinda immersion breaking. Also maybe have some recolored fulgoran ruins as broken structures would add some nice detail. Can just have them give you nanites when you mine them.
Circa: I feel like adding some trees would be neat as well as rocks. water on the left side and cliffs on the right would also add some depth but with the current width of the "planet" I understand that could make some impassable walls. And also It would sorta mess with the way you get water from the "planet". But having it be completely flat looks a bit off so at least some trees and rocks would be nice.
Nix: Actually not bad, all the ice chunks help keep it from being a completely flat surface. Maybe a Cliff or two would help but still alright as is for now
Also I feel like adding some music would help. Can pick tracks from already existing planets.
I feel for Neumann V can use the space theme, Circa can use Nauvis, and Nix can use Aquillo.
Also changing the sound the robot spawners make from the default biter nest noises would be appreciated.
So far though the mod is really need and I am interested to see where it goes from here. Best of luck!