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 John Carpenter
Halloween · The Thing · Escape from New York · They Live
medium
Found-footage horror
The Blair Witch Project · Cloverfield · REC · V/H/S
Each of these films is presented as recovered footage shot on cameras the characters were holding when things went wrong. Shaky lenses, dropped audio, and the question of who edited the tape are all part of the story.
hard
A crime reconstructed through conflicting accounts
Rashomon · The Last Duel · Hero · Courage Under Fire
Each film hands the same event to several witnesses and lets their versions disagree. The audience never gets one settled truth, only the gaps between the stories. Rashomon set the template in 1950 and the others apply it to a medieval duel, an assassination plot in ancient China, and a Gulf War friendly-fire investigation.
tricky
Opens with the ending, then works backward
Sunset Boulevard · American Beauty · D.O.A. · Carlito's Way
Each of these films shows you the protagonist dead, dying, or already ruined in the first scene, then spends the rest of the runtime explaining how they got there. The voice-over often comes from someone who, by definition, should not be talking.