Quoted from chuckwurt:Have the upside down be like a lower playfield similar to Haunted house or black hole.
The UV light with reactive paint is a good idea too.
I also wonder if stern just snatches up licenses even if they might not make the pin. Especially now that it's more competitive. Snatch up the license when it's cheap and stock it away. I wouldn't be surprised if they already had the license.
The upside down should be a lower play field that isn't visible. Then when the ball goes to the lower play field that portion of the playfield flips over to reveal the upside down. Have no idea how you'd do that but I want it.