Binding of Isaac Achievement: Marrow
In-Game Secret Number
Use I - The Magician or Telepathy for Dummies while already having homing tears (Sources of this effect include I - The Magician, Telepathy for Dummies, Spoon Bender, Sacred Heart, or Godhead).
Acquire Blood Clot 10 times
Unlocked new enemies!
Defeat The Lamb for the 1st time
Defeat Ultra Greedier as Keeper
Take 50 devil deals
Complete the Boss Rush as The Forgotten
Defeat The Lamb without taking hearts, coins, and bombs through an entire run
Defeat Ultra Greedier as Azazel
Beat Chapter 4 without taking damage
Collect every entry in the Bestiary (Bugged v190 - Mobs that don't exist in the bestiary are being counted. This allows Sin Collector to be unlocked without a complete bestiary)
Take 25 items from Angel rooms
Participate in 31 Daily Challenges (they don't have to be consecutive; it will still count if you die in the first room)
Increase in size 5 times in a single run. Sources of increased size include "One Makes you Larger" pills, XI - Strength, and Magic Mushroom
Unlocked a new area.
Defeat Hush for the 1st time
Alt stage to the basement.
Defeat Mom's Heart 11 times
Defeat Isaac as Apollyon
Unlocked a new co-player baby.
Earn all Hard Mode Completion Marks as Apollyon
Use cards and runes 20 times
Defeat Satan as The Forgotten