A game where you play as an existentialist, fatalistic French writer dealing with a drug problem.
Quick! Press A to overdose... OVERDOSE!
Honestly though, I would maybe like to see a game where the "character" is just a disembodied spirit thing that you control and the main goal is to join the mind and body of various people, inhibitting their life as you're waiting for a time to start your own. So there's really practically infinite means to have characters and play styles and such. The goal is to eventually, through those people you interact with and the actions you can have them do, create a society, be it in a small community or globally that you would like to live if you actually existed and then find a couple of people that you would most like to be the progeny of and create all circumstances correct for them to date and mate and marry so you can enter that child they produce in the womb before it gets a different soul and there, you win.
You're a human baby in your perfect human world!
But, truly, that idea is too insane to ever have anyone but myself to be interested in.