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
Developed by Valve
Half-Life 2 · Portal · Left 4 Dead · Team Fortress 2
medium
The Game Awards Game of the Year
Overwatch · God of War · It Takes Two · Baldur's Gate 3
hard
You were the villain all along
Star Wars: Knights of the Old Republic · Spec Ops: The Line · Undertale · Braid
Each game delivers a twist revealing that the player character is the villain or monster of the story: in Knights of the Old Republic you are Darth Revan, the Sith who started the war; in Spec Ops: The Line Captain Walker's atrocities make him the very monster he was sent to stop; in Undertale's genocide route the player embodies Chara and is revealed as the true villain who seeks the destruction of everything; in Braid the ending reveals that Tim is the monster the princess was fleeing all along.
tricky
Title begins with DARK
Darkstalkers · Darkwatch · Darkest Dungeon · Darksiders
All four game titles open with the letters D-A-R-K: Darkstalkers, Darkwatch, Darkest Dungeon, and Darksiders. Four entirely different genres and studios, all hiding the same prefix.