Binding of Isaac Achievement: Angry Fly
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).
Unlocked even more bosses!
Defeat ??? as 6 different characters
Unlocked a new challenge.
Defeat ??? or The Lamb for the first time
Defeat Ultra Greedier as The Forgotten
Blow up doors and secret room walls 50 times
Defeat Isaac as The Forgotten
Defeat Ultra Greedier as The Lost
Defeat Little Horn 20 times
Defeat Ultra Greedier as Isaac
Have 20 blue flies at the same time
Beat Chapter 3 without taking damage
Complete the Boss Rush as Apollyon
Defeat Delirium as Cain
Defeat The Lamb in under 20 minutes
Defeat Delirium as Azazel
Complete challenge #33
Defeat Delirium as Eden
Defeat Delirium as Isaac
Unlocked super special rocks.
Get a 5-win streak, using a different character for each win