I Have always wanted to create a game with tons of openness. Kind of a mix between Dishonored, Thief, and We Happy Few. You have an entire active city where people actually have goals and daily jobs and such. It would be cool to have everything time based, so stuff happens even if you're not doing anything, and even be able to live a practically normal life, get a job, make friends. See news happen, and perhaps in the dead of night you turn into an assassin and prevent events from happening that could kill many people. And so on. Just being able to watch the city lively at work and NPCs actually having goals to complete each day, it would be so interesting. I suppose Skyrim is the closest game to my idea as of current