Achievements

For tips and strategies on completing achievements, see achievement tips.

Achievements are unlocked for players after completing challenges, reaching certain milestones, achieving hidden goals, or unlocking certain items. In the PC version, every Steam achievement exactly corresponds to one secret in-game, whereas only a handful of secrets are represented by PSN trophies in the Playstation version of the game.

If you are unable to unlock achievements, a small icon of a crossed-out trophy will be displayed below your keys counter. Conditions which can disable the ability to unlock achievements include:
 * Using a pre-determined seed. Certain cosmetic and difficulty-increasing special seeds will still allow unlocks.
 * During a Challenge, although the achievement for completing the challenge is unaffected.
 * Playing with any enabled mod (unless Mom has been beaten).
 * During Victory Laps.

Rebirth has a total of 178 unlockable secrets. Afterbirth added 98 new secrets, for a total of 276. Afterbirth † added 63 new secrets, for a total of 339. Booster Pack added 64 new secrets, for a total of 403. Repentance added 234 new secrets, for a total of 637.

At the stats screen, pressing Alt + F2 will sync your unlocks with your Steam achievements. If you have Steam achievements for secrets you haven't unlocked ingame, they will be unlocked by doing this.

Trivia

 * Each achievement is color-coded based on the requirements for unlocking their respective secrets:
 * Tan: Random/Miscellaneous unlocks
 * Tan with blood stain: Mom's Heart/It Lives! on Hard unlocks
 * Olive-Green: Character unlocks
 * Dark Red: Mom's Heart/Womb ending unlocks
 * Grey: Isaac unlocks
 * Black: Satan unlocks
 * Dark Blue: ??? unlocks
 * Purple: The Lamb unlocks
 * Pale Green: Boss Rush unlocks
 * Pale Blue: Hush unlocks
 * Orange Yellow: Greed Mode unlocks
 * Orange Yellow with blood stain: Greedier mode unlocks
 * White: Delirium unlocks
 * Red: Mega Satan unlocks/accomplishments
 * Bright Yellow: All Hard Mode marks (most are tan)/Damageless floor/100% unlocks
 * Brighter Yellow: Greed Donation Machine unlocks
 * Bluish Purple: Challenge unlocks
 * Dark Green with bloodstain: Mother unlocks
 * Orange: The Beast unlocks
 * Bright Purple: Tainted Character unlocks
 * Despite being a Boss Rush unlock for, 's achievement color is bluish purple, a color normally used for challenge-related unlocks.
 * Achievements 37-41 and 83 have a typo on their pop-ups, and read "achieveved".
 * Although not technically an achievement, getting 1000000% for all 3 save files will result in a special 3,000,000%!!! graphic on the save file selection screen.
 * The 5 Nights at Mom's achievement is a reference to Five Nights at Freddy's.
 * The Mr. Resetter achievement may be a reference to Mr. Resetti from the Animal Crossing series.
 * The Something Wicked This Way Comes quote is most likely a reference to the same quote from one of the witches from Shakespeare's play "Macbeth."
 * Afterbirth+'s Booster Pack added 64 secrets. Interestingly, this is a single secret more than Afterbirth+'s original count of 63 secrets. Thus, this update more than doubled the amount of secrets added to the game.
 * Achievements 340-348 don't exist in the PS4 version, resulting in the content already being "unlocked" even on new save files.
 * Achievements 340-348 don't exist in the PS4 version, resulting in the content already being "unlocked" even on new save files.