It's a crime this game is not on GoG, don't understand the reason since it's DRM free and it's in other places.
A really good old game that inspired the birth of many others, like Rimworld or even Minecraft I think. I've been a supporter for years, donating when the game was only free, I keep donating but I also bought the new version with improved UI and would love to have it in GoG also.
You can spent hundreds of hours and never get bored, you even start to see it's magic, how it really seems like the dwarves have personalities and intent that justifies their decisions....it's quite the feat. It still needs some improvements and content is lacking in some deeper aspects, like law or crime investigation, but you will surely can count on the devs to keep at it for another 20 years of improvements.