"The biggest influences for ONI were games like Prison Simulator, Sims, and Dwarf Fortress, from this old article on the game: https://hardcoregamer.com/previews/pax-kleis-oxygen-not-included-is-incredibly-complicated-and-awesome/225305/
I'd like to see some elements of The Sims in the game, where dupes establish relationships and rivalries with each other. Examples include...
Nisbet having a "crush" on Max, which causes a positive moodlet for Nisbet when near Max (-10% stress, near crush)
Dupes feeling concern for others, which will make some go out of their own way to help. For example, if I steam Max in an enclosed glass chamber full of 500C / 932F steam, other dupes can clearly see he is being steamed to death. More caring dupes who see him will stop what they're doing and free him. If he's downed, they'll automatically bring him to an available med bed. Dupes with high medical skill can rush to the scene after word has spread, get him to a safe area instead of a triage cot, attempt to heal and prevent certain death. Because Max can now move, he can be ordered to recover on a triage cot. This can reduce micromanagement on my part in case I screw up or if some random dupe decides to put Enriched Uranium in the nuke reactor while the insulated wall is still under construction and the 5 dupes working there get incapacitated due to extreme radiation exposure hahahahahaha
Bubbles making fun of Meep's ugly face, which starts a brawl between the two. HUGE decor penalty in a large area worse than heavi-watt wires, objects and walls being damaged or destroyed along the way, huge stress increase for both during the brawl (+50% stress?), the two turning into enemies, which causes an increase in stress if they're near each other (+10% stress, near enemy), and an increase in stress to any dupe who saw the fight (+10% stress, saw friends fight) and more. The victor however, will get a large positive moodlet for a while (-25% stress, won a fight), while the loser gets a large negative moodlet for a while (+25% stress, lost a fight). Sometimes, Bubbles and Meep's friends can join the brawl and even more chaos happens!
Dupes can comfort others when they notice their stress levels are above 60%. This can open up a separate branch of the medicine skill. A medical facility specializing in mental health and stress relief is possible as a result, which can be an upgrade to the massage clinic if the psychologist dupe itself isn't stressed out.
Additional traits like Clumsy, Masochist and Joker. A clumsy dupe occasionally trips and falls (-1 health per trip/fall), which may cause nearby dupes to laugh and have a tiny positive moodlet for a short duration. A masochist dupe desires pain. The more injured, the greater the positive moodlet. And a joker makes other dupes laugh, causing a decor bonus and stress relief to nearby dupes. They can do comedy in a rec room or great hall either in empty space or a recreational structure to further increase the decor bonus and stress relief. Combining all three traits together results in an Ari hahahahaha!