: Reaching the end of the Corpse lead to a fight with The Witness (later renamed Mother in Repentance ), a terrifying multi-phase encounter in a uniquely zoomed-out boss room.

Before The Binding of Isaac: Repentance redefined the basement, there was . Released in 2016 by a small, dedicated team—including lead developer Kilburn —Antibirth was a fan-made expansion for The Binding of Isaac: Rebirth that felt so official, Edmund McMillen eventually hired the team to turn it into the game’s final DLC. What Made Antibirth Special?

: Players could explore entirely new chapters like Downpour , Mines , Mausoleum , and Corpse , each featuring unique enemies and a much higher difficulty curve.

Antibirth introduced two of the most mechanically complex characters in the series: The Binding of Isaac: Antibirth — Hi, long time no see