Jim Trailerpark said:
Rimworld looks dreadfully similar to Prison Architect. Is it made by the same guys?
Nope, the developer just wasn't good enough in doing art for the game to create his own graphic style, so that the art he made on his own was heavily inspired by PA. Part of the reason he did a kickstarter was to get enough money to hire an artist for the game. He has the artist now but the fans liked the overall style of the visuals so the visual style is still pretty similar to PA. I think he even asked the PA artist if it's ok.
It's completely different in gameplay though and in my mind a lot better. At least i have gotten bored with PA way way faster than Rimworld and have not gotten interested enough to continue playing, while i played every new rimworld alpha.
On Topic:
I can aggree with a lot of mentions here:
Dwarf Fortress
Rimworld
Factorio
All these games are unfinished, sold and great nonetheless.
Though i want to mention
Stonehearth
It's still really early in development and a lot of stuff is not in place yet. But it's allready pretty fun, although for roughly one to two hours at most, since there isn't much content. Additionally the developers are very open in their development which in my opinion is integral to keeping the trust through a long time of early access development.
They release a video update about new features pretty much every week and have recently started to livestream their development two times a week. You can literally watch the developers fiddle with the code and models of the game for a couple of hours two times a week.
This is also a reason why i think that Rimworld is so great, because the developer releases the changes he made during development every day.