Rimworld is a very nice base building game, which gained a enormous amount of popularity from the get go due to the similarities to another quite popular game (Dwarf Fortress) and excellent game design (to make the game somewhat challenging every game you play is supervised by a AI director which more or less does the same thing as the one in L4D). The game as also expanded tremendously as of now due to three DLC packages which add a lot of fun gameplay:
- Nobility (Royalty)
- Belief systems (Ideology)
- Pregnancy, biotech and genetic modification (Biotech)
The game also has a pretty big modding community.
If you like sims you def are going to love it.
And if you happen to be interested in a deep dive into the game design principles behind Rimworld Tynan Sylvester (the designer/developer) wrote a entire book about it: https://tynansylvester.com/book/
