The Binding of Isaac

The Binding of Isaac is an almost top-down game that borrows heavily from the roguelike genre. Players explore dungeons that consist of a series of connected, single-screen rooms with randomized environments, items and enemies for each gameplay session. Like the original games death is final and the player has to restart the entire game to continue. Each game consists of five series of dungeons leading up to a final confrontation. Each dungeon has a boss and defeating it opens a staircase to descend to a new environment.

The story is based on the one from the Hebrew bible where God asks Abraham to sacrifice his son Isaac. In the game Isaac is a young boy whose mother is called by a voice to kill her son to prove her allegiance. The introduction however hints that it is only the boy's imagination as he draws the scenes on sheets of paper. In his story, Isaac manages to flee from his mother by escaping through a trap door before she can kill him. That way he ends up in a dungeon and he has to find a way to kill her.

Players control Isaac through four movement keys along with four additional ones to fire in the four main directions. Isaac attacks monsters by launching his tears. There is a slight delay in the firing, so that combined with movement it is possible to launch the projectiles with a bend trajectory. Isaac can collect hearts to maintain his health level, upgrades for his tears (triple shot, more damage, charge, mirror to make them retract their path, ... ) and coins to purchase items at Zelda-inspired shops. Other items such as bombs, pills with various effects, and keys are left behind by opponents. The pool of possibilities is very large, making each gameplay session completely different. There are also special items to be found such as a magnet to draw in items, or companions that help fire at enemies. Certain ones have drawbacks, such as transporting Isaac back to the starting area or reducing the amount of hearts in exchange for additional lives. Isaac can also discover hidden rooms and secret environments.

The game keeps track of the discovered collectibles and secrets, and allows the player to review these. Next to Isaac, three additional playable characters can be unlocked, with names based on the biblical tradition: Magdalene, Cain, and Judas. They each present a different class with a different playing style. There are also multiple endings.