My playtests (mechanical only, no narrative yet) are running 5 to 10 minutes - I flew through a bunch just to get a feel for the win / loss rate, whether or not the *game* underpinning my storytelling is fun. Figuring 20 to 30 minutes will be the landing point once people are narrating each of 10 to 18 turns . . .
I think one part of average place time really depends on how much the player wants to build on a narrative vs. more mechanically clear all cards and reach the end goal. I could see that adding greater variability in the play time, especially if the card prompts you to journal or reflect on something.
