"One of the greatest pleasures of cinema (and one wholly specific to this art form, that can't be found in any other medium) is the ability to transport the viewer into epic narratives that span dozens of different locations and time periods. And while a novel can contain the same narrative, the visual component of cinema makes it an incomparable experience of its own.
So a movie set in a single room presents a challenge that, when done well, can prove to be extremely rewarding. There are numerous examples of that in film history, of celebrated one-set movies from "Grand Hotel" to "Green Room," but, as with all genres and subgenres, there's also great stuff that for some reason or another doesn't generate the same acclaim, no matter how deserving."
