My issue with Rimworld is getting the game going. So often I'll start a world, get a small base going, then realize I could have done something better than want to start over.
That's the beauty of Rimworld though. You
can do everything right - build the perfect base with the perfect pawns, but one event takes everything down. You can't play any game with hindsight in mind because there's likely something you could have always done better but there's always a next time. Hell, my last run on Rimworld I was about 10 minutes from leaving the planet and in a bout of stupidity, I wanted to fire off my last Doomsday Launcher before I left and I accidentally told my pawn to target the enemy that was right next to my main base generator and the shuttle... Needless to say, losing that generator caused half of my turrets to go down and then I was overwhelmed.
Besides, if you get a game going and realize you could have done something better, there's really nothing stopping you from simply starting over or saving right as soon as you land and play it out how you want.