Spoilers ahead: for the puzzle and the movies/games
This page reveals all categories and answers for this puzzle. It also discusses plot details, story endings, and other spoilers for some of the movies/games shown.
easy
Set in Rome
Roman Holiday · Bicycle Thieves · La Dolce Vita · The Great Beauty
medium
Score by Bernard Herrmann
Fahrenheit 451 · Marnie · Sisters · The Ghost and Mrs. Muir
hard
A double becomes the obsession
Dead Ringers · Enemy · The Double · Us
These films all start with a second self, then let that second self take over the room. The double is the premise, but obsession is the real engine. Once the split appears, nobody gets to live normally again.
tricky
The ending is a performance
The Red Shoes · Billy Elliot · Whiplash · Another Round
Each film saves its last emotional jolt for a performance. Sometimes it is a concert, sometimes ballet, sometimes a dance, but the ending only lands once somebody steps in front of an audience.