It's worth mentioning that the author has a YouTube channel[1] where he periodically posts videos showcasing updates he's made to the game over time. I'm surprised there isn't a link or even any kind of screenshots of the game on the Github repo, even if it is still very early in development.
Agreed, this repo is in desperate need of a few screenshots/video on the ReadMe to showcase what it looks like.
I personally have found there is something of an art to a good readme. So folks can make one that is informative and visual, others can't. I have a project or two that suffered because my readme designing skills suck, then talented friend PR'd a great readme with screenshots and such.
It may be an art, but I wouldn't say it takes much talent to include a screenshot, GIF or YouTube link! Most likely he just didn't give it much thought.
Speaking only for myself, often a project is in a half-finished state, and any provided screenshot would quickly become out of date.
You could probably automate a tool to take screenshot for you.
Sounds something like charm’s vhs:
https://github.com/charmbracelet/vhs