A big leak from MP1st on Dec 27, 2025, shared by TheGamer, hints BioShock 4 heads to Borealis—a snowy Antarctic city in the 1960s. It shows casino areas, a Solaris district, and huge canyons with industrial looks. ADAM, the magic goo from old games that twists people, might return too. New bad guys called Flushers act like crazy Splicers, and leaked pics tease a hero in a gray suit plus a golden villain statue. Dev had big problems before 2022, but it's back on track.