So, you want Universal to pay for the Backrooms license—justified by the success of the movie—but not adapt the movie and instead do an original take on Backrooms? At that point, Universal might as well save the money create an entirely new “liminal spaces” original not tied to Backrooms.
After seeing the movie how a walkthrough adaptation can “exist,” but I don’t think it would actually be any good (or importantly, memorable) based on how Universal is forced to design houses. I actually think the Fallout example is pretty apt. Fans wanted a thirty-foot vault door and vast vista when entering the Wasteland. What they got was… not… that… The first room in Backrooms, at appropriate scale, would take up a third of a traditional house footprint. And if you want it to be appropriately bright, it actually needs to be built to scale or else it’s immediately disappointing. You can have clearly defined settings… but barely (by the IP’s design).
Close adherence to the film (and thus the IP) would likely result in a house that struggles to meet fan-expectations, and a not memorable, confusing experience for casuals. Giving the IP a larger dedicated SS would address scale, but likely wouldn’t increase the overall experience. It would still only be 1–3 performers a room (now further away) in a Congo line.
Although, now that I think about it… they could go meta with an adaptation…
Instead of adapting the movie, it could be an adaptation of how we remember the movie. That could allow more compressed, darker rooms and aggressive characters. Communicating that becomes tricky, but it does give an out.