The Binding of Isaac: Antibirth is a fan-made expansion for the popular game, offering players a deeper and more challenging experience. This expansion introduces two new characters, each with unique playstyles, and over 90 new collectible items that enhance gameplay. Additionally, players can find and utilize more than 18 new trinkets, providing new strategic options as they navigate the perilous environments.

In total, Antibirth adds over 80 new enemies and 16 new bosses, significantly increasing the game's difficulty. Players can explore more than 4000 new rooms, uncover a secret final chapter, and discover greater secrets than ever before. The expansion also features improvements for local cooperative play and a nearly complete original soundtrack that captures the essence of the classic Isaac experience.