Undertale (2015)

Every fight can end without anyone dying, and the game watches how you treat its monsters more closely than any RPG has a right to. A child falls into the Underground, a kingdom of monsters sealed beneath a mountain, and battles are bullet-hell dodging in which mercy, flirting and patience all count as moves. Toby Fox's writing is funny first and moving when you least expect it, over about six hours. Which ending you reach depends on what you did, and for the warmest, go True Pacifist: spare everyone, befriend whoever lets you, and follow the extra steps the game hints at after a Neutral ending.