As far as i can see, there is no scaling option inside the game, nor its possible to change screen res for the game itself.
If set the "screenwidth" and "screenheight" in the startup file, the game will work in window mode only.

Sadly ist nearly impossible to play the game under 4k at that moment sicnce only a minority of text will be scaled if ui-scale is activated under windows. most of the text remains too small to be readable

Is it planned to add screen options inside the game in the future ?.

Judging from other posts around the internet and their age, I suspect not. Non-scaling text appears to be a well known "discovery" (i.e., you don't know about this problem at purchase, but after you install the game and begin to play at higher resolutions, you soon encounter it and search for a solution; you then find it a commonly held and persistent problem as the text size is rumored to be hard coded in the game itself - it cannot be modded).

I'm going to necro this post to share this fix for Windows 10 on 4k resolution, seems to work like a charm!

- Open the game folder (through the launcher or however you like)
- Rightclick on DistantWorlds.exe (with the blue icon in front)
- Select "Properties" and go to the "Compatibility" tab
- Click "Change settings for all users" at the bottom
- Click "Change high DPI settings"
- At the bottom, check "Override high DPI scaling behavior" and select "System (Enhanced)" in the "Scaling performed by" dropdown box
- OK your way back and things should look peachy when you start the game

Originally from Steam forum, can't seem to post the link for credit. NOTE that if the "Override high DPI scaling behavior" checkbox is grayed out, you didn't click "Change settings for all users" first.