Hi, first of all correct me if this thread has already been opened somewhere else. If not, well one thing came to mind. What if there could be some in game activities, such as Chess, Texas Hold'em and 8 Ball Pool in the game world. They could be pre-defined models you could purchase or craft in the game. This would bring more reasons to come to play. I don't know if you guys have heard of a game called Puzzle Pirates. If not well it's pretty much what the name suggests: Being a pirate and sailing while doing various puzzles etc. anyway in that game I think this was implemented brilliantly. If I wanted a break from sailing and pillaging then I could just go to the nearest tavern and play some game like Texas Hold'em among few others and relax, completely away from the sailing stuff.
This would also bring meaning to some of the buildings in a city or a colony. For example there could be a community hall, where players could gather between their travels, sit down and play together. Some variety to the game + at least something as a heritage from planet earth.
Well this is just one idea among others and could obviously be implemented later as there are 1000 more important things right now, but anyway.