Heartbound (video game)
"Every time you interact with an object, talk to an NPC, forget to turn off a light-switch, take out the trash, or disregard a sparkly bush the game remembers this and will change subtly for all further interactions. The greatest part about this design is that it already works and is in the current builds of the game. Both minor and major differences are going to pop up throughout the game and give the community something to share with one another. Everything you do matters no matter what kind of player you are or choose to be."