Previous writing 
If there's one game you wish you could have been a part of creating, what would it be? For me it's gotta be Breath of the Wild, everything about the concept, the aesthetic and mechanics screams something I love about games (ok except maybe narrative).
I'm gonna have to go for the surprise answer much like @TheRishiBarnwal and say Ori and the Blind Forest. Having a hand in creating one of my most beloved narrative designs would have made my heart so full 
