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
Directed by Martin Scorsese
Goodfellas · Taxi Driver · The Wolf of Wall Street · Hugo
medium
Based on a Stephen King story
The Shining · Misery · It · The Green Mile
hard
The protagonist discovers their reality has been fabricated
The Truman Show · The Matrix · Total Recall · Free Guy
In each film the protagonist finds out the world they're living in isn't real (built around them as a TV show, a computer simulation, implanted memories, or a video game) and has to figure out who they are now that the setup is gone.
tricky
Secret Shakespeare adaptations
The Lion King · 10 Things I Hate About You · She's the Man · Forbidden Planet
Each film is a loose modern adaptation of a Shakespeare play (The Lion King from Hamlet, 10 Things I Hate About You from The Taming of the Shrew, She's the Man from Twelfth Night, Forbidden Planet from The Tempest), but none of the titles reveal the original source.