Quick Answer
What changed from the first game
The first game follows Charles Reed through the open-world city of Oakmont and emphasizes freeform detective cases. The sequel changes the protagonist and setting, then rebuilds the experience around survival horror, scarce resources, combat, locks, and a sequence of large interconnected levels.
Because the opening establishes Calvin and Faye's ritual directly, it does not assume that the player remembers the first game's individual cases or three ending choices.
What still connects the games
Both titles use the Sinking City name, Lovecraftian mythology, supernatural flooding, investigation themes, and Frogwares' universe. References and optional post-game lore reward returning players, but they function as added context rather than required homework.
The most accurate description is a standalone sequel: mechanically and narratively new, but intentionally part of the same broader mythos.
Sources
Facts were rewritten in original English and checked against the following pages. Store values can change after this snapshot.