Binding of Isaac Achievement: 7 Seals
In-Game Secret Number
Participate in 31 Daily Challenges (they don't have to be consecutive; it will still count if you die in the first room)
Alt stage to the womb.
Defeat It Lives 30 times
Defeat ??? or The Lamb for the first time
Defeat Ultra Greedier as Apollyon
Defeat Delirium as Eve
Complete challenge #35
Unlocked a new co-player baby.
Earn all Hard Mode Completion Marks as Apollyon
Complete challenge #33
Have The Battery, 9 Volt, and Car Battery in your collection
Defeat Mom for the 1st time
Unlocked new bosses!
Defeat ??? as 3 different characters
Unlocked even more bosses!
Defeat ??? as 6 different characters
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).
Defeat Isaac 5 times
Defeat Ultra Greed as The Forgotten
Defeat Hush as The Forgotten
Complete the Boss Rush as Apollyon
Defeat Isaac as Apollyon
Alt stage to the caves.
Defeat It Lives 16 times