BioShock 2 takes place ten years after the events of the first game. You play as Subject Delta, one of the first Big Daddies – massive, armored creatures created to protect Little Sisters. Unlike the first game, where you were an ordinary person, here you become part of Rapture's grim system. Your goal is to reunite with a Little Sister named Eleanor Lamb, who is your "daughter" in a symbolic sense. The game's story explores themes of family, responsibility, and free will. At the center of the narrative is the confrontation with Sofia Lamb, a new antagonist who represents the ideological opposite of Andrew Ryan. Sofia believes in collectivism and sacrifice for the greater good, creating an interesting contrast to Ryan's individualism. The player must make choices that will influence the game's ending, emphasizing the importance of moral decisions.
