The Binding of Isaac has 97 Secrets (As of Wrath of the Lamb v1.48) that can be unlocked. Secrets can add differents kinds of things to the game, such as Items, Bosses, Characters, etc.
In-Game Secrets List (98)
Basic Progression Unlocks
Character and Combo Unlocks
Game Completion Unlocks
Special Bosses and Loot
Separate Task Based
No Damage Achievements
Halloween Update
(Some of these may be wrong)
Wrath of the Lamb In-Game Secrets List (34)
Characters
Game Completion Unlocks
The Chest
Challenges
Task Based
"Guppy's Hairball" - Transform Isaac into Guppy. (Collectible item)
"Dad's Key" - Complete the Chest with any character. (Activated item)
"!Platinum God!" - Collect 197 items and unlock all other 97 secrets.
Platinum God! Achieve the "!Platinum God!" secret (New Backdrop)
"A Forgotten Horseman" - Destroy a total of 30 Tinted Rocks. (New Boss - Conquest)
"Something Icky!" - Complete the Womb or Utero 15 times. (New boss - Triachnid)
"The Left Hand" - Unlocked by defeating Ultra Pride. (Trinket)
"Stop Playing!" - Kill Mom over 200 times (New backdrop).
Bugs
- Secrets might be missing even though they have already been earned, due to various Anti-Virus programs, CCleaner (Or similar cleaner programs) or Steam's Cloud Sync.
- For a detailed description on how to fix the missing secrets, check the video below.
Videos
The Binding of Isaac PSA 1 - Missing Secrets Fix
