I'd make an interactive simulator, a la Thief and Dishonored (but better), with the gritty, pragmatic world flavour of Gothic 2 (but better), with many actually branching and interconnected storylines, and the ability to complete the game without having to resort to violence. I'd also make sure that characters and relationships are realistic and well-written.
The literary equivalent would be...
Game of Thrones meets
Perdido Street Station meets
The Wheel of Time meets
Ghormenghast.

OR
I'd make a mundane modern simulator, where you act out the life of one of a number of predetermined people in their relationships, job and aspirations. It would be a mix of...
The Sims meets the relationship simulator of
Persona meets
Hard Rain. And yes, you would have lots of stats, but they would almost never be used for combat/violence.

GIVE ME MONEY AND APPOINT ME AS THE LEAD OF THESE DREAM PROJECTS, ANYBODY!
