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 Stanley Kubrick
2001: A Space Odyssey · Full Metal Jacket · Eyes Wide Shut · Dr. Strangelove
medium
Score composed by John Williams
Star Wars · Jurassic Park · E.T. the Extra-Terrestrial · Harry Potter and the Sorcerer's Stone
hard
Shot in black and white by choice
Raging Bull · The Artist · Roma · Nebraska
Each film was shot in black and white by choice, decades after color became the industry standard. The four span 1980 to 2018. The connection isn't that they're old; it's that their directors picked the format for the story.
tricky
Title is also an iconic pop song
Stand by Me · Purple Rain · Yesterday · Bohemian Rhapsody
Each film's title is exactly the title of a famous song: Stand by Me (Ben E. King), Purple Rain (Prince), Yesterday (The Beatles), Bohemian Rhapsody (Queen). The films and songs have nothing to do with each other, which is why the overlap is easy to miss.