I saw "The Black Phone" and, while it is not the masterpiece I expected (considering the acclaim surrounding it) it is a very well done movie, with great acting by everyone involved and a nice story that develops logically (a rarity these times). There is a lot of padding, as it is the main story of kid vs. serial killer that is interesting but it covers one hour of run time. The parallel storylines are not boring but clearly arbitrary (I won't spoil, but you can see how they had to reach the 90 minutes mark). Also, there are strong "Stranger Things" vibes - not because the movie is mostly about kids but because of the way the story is shot and told. These events could be happening elsewhere in the world of ST.
The premise is good for a RPG session with one player and one GM. It is the classic "Escape Room" scenario. We are in the late 1970s. A kid is kidnapped by a serial killer called "The Grabber" and imprisoned in a cellar. He knows that he will be killed in a few days, so time is precious. In this cellar there is a disconnected black phone, but this kid starts getting calls from ghostly entities - the previous victims of The Grabber. Each one of them gives him some suggestion about how to escape: they failed, but if the kid acts better and faster maybe he can save himself...
The movie is basically this RPG scenario played out on the screen. The kid can't just rely on the suggestions by the ghosts because they are incomplete and didn't work anyway. It is up to him (or her: gender is not important) to put everything together, add his own findings in the cellar, think a bit out of the loop and find his way out. The movie lays out a lot of peripheral info too, about "The Grabber", his character and his surroundings, which can be useful to a GM if the player tries different routes. Time is crucial but also how the kid behaves is important, as it is clear how "The Grabber" will give him more time or kill him on the spot according to precise whims. In a game, reaching desperation but delaying death can be an interesting dynamic.
Definitely suggested, especially to GMs, but also because of its own merits.