I'm not sure if this is still being actively developed, his last post was on Feb '22. In any case, I'd like to add to the encouragement in this thread. I find the design intriguing.
He probably realized how much work you actually need to do and quit, can't blame him
I have a game largely also inspired by Fallout, though more so by Duck Nukem.
Allow me to sum up Redaxium's dev history prior to public demos.
1) Created all my huge terrains first.
2) Textured them so they had decent variety, even if ugly.
3) Focused on polishing the first terrain thereafter for a long time.
4) Avoided the mistake of both discussing and showing my work.
5) Redacted.
If I said guess what codex i'm making a game and it will be like Fallout! No one would have believed me.
Games take years to make. A complex one with a unique art style, or in case of OP a HQ artstyle taken even longer, esp. if you're a solo dev.
I spent years drafting posts on this website that I never pressed submit on. This included many posts had everything from insane, even psychotic rants
about how gamedev and/or the world in which I must live. And prior to that I spent years of silence not submitting
my true thoughts on all sorts of subjects because I knew one day I would make a game, and I needed to not be institutionalized before I finished it.
A lot of gamedevs openly develop their game. They have a blog or a youtube channel. This does wonders for marketing IF YOU DON'T BITCH OUT.
But then you're wasting serious time on perfecting scripts about what you will say, and trying to balance promise with hype/delusion.
Editing videos and worrying about your influence, and not the product itself is probably a good way to WANT TO BITCH OUT.
Let me tell you what it's like to be a gamedev who never shipped a game, and is working on something ambitious.
You know there's a huge chance you will not only never finish due to technical reasons, but due to the fact of how unlikely it is you can
stay disciplined in changing/distracting world. You can't rely on others because they will undermine you. That includes Codex btw.
Gamedev is like fighting giant unkillable zombie nonstop for years in a row. And it is destroying your life opportunities every second
as price of admission. Cool on paper miserable in reality.
If you aren't "prepared" to die having more lifetimes of anguish than the rest of your life will ever make up for, don't do multiyear gamedev solo project.