#isaacfacts

If you save and quit in Mother's room right after beating her, the boss door reappears.

You can use this to play the self-sacrifice room and go to the Dark Room, progressing your run further than Corpse II.

This also still counts for the Mother post-it unlock as well.

In the Binding of Isaac: Repentance files, Mother's sprite sheet has an unused sprite of her flipping you off.

If Isaac dies to a Grudge, he explodes into bits and pieces of meat.

This death animation is unique to Grudges, so if you want to see Isaac exploding without any mods, be my guest!

Happy New Year!

You can celebrate with some fireworks by donating 999 coins to the Greed Donation Machine.

If you check the room names for the Mines Chase in The Binding of Isaac: Repentance, all of them have names describing the room layout.

For example, Mineshaft Room (big straight), or (big curve).

Funnily enough, however, there is one room called Mineshaft Room (big hetero).

The orange champion variant of Little Horn damages himself very slightly when he spits out a bomb.

You can use this to your advantage if you're really really patient.

Is he stupid?

The profanity list for The Binding of Isaac: Repentance's Co-op is lifted straight from Minecraft's profanity list, meaning you can't say certain items or terms that Isaac uses with the in-game text chat.

The text that appears when you activate the item "Whore of Babylon" and the Reversed Empress card come directly from Castlevania II: Simon's Quest, right down to the UI.