Full list of all 48 Cult of the Lamb achievements. It takes around 15-20 hours to unlock all of the achievements in the base game on Windows.
The base game contains 37 achievements, and there are 2 DLC packs containing 11 achievements.
No longer a servant, no less than a God.
Unlock all fleeces.
Beat Shamura without taking damage.
Unlock all tarot cards.
Unlock all Follower Skins.
Beat Kallamar without taking damage.
Beat Heket without taking damage.
Beat Leshy without taking damage.
Defeat the One Who Waits.
Gain 20 Followers.
Defeat Shamura.
Defeat all opponents in Knucklebones.
Take confession.
Cook a Follower meat meal.
Find all 5 locations.
Sacrifice 10 Followers.
Defeat Kallamar.
Unlock all curses.
Unlock all weapons.
Catch 1 of every fish.
Unlock all doctrines.
Defeat Heket.
Fully Upgrade Cult.
Have 666 gold coins.
Unlock a new fleece.
Reignite the lighthouse.
Defeat Leshy.
Sacrifice a Follower.
Salvation awaits the fallen soul.
Gain 10 Followers.
Win a game of Knucklebones.
A new world awaits.
Gain 5 Followers.
Let the Word be known.
Defeat the first mini-boss.
The first devotee to the Cult of the Lamb.
A deal that cannot be undone.
Complete a row in Purgatory.
Collect all Relics.
Get your Gold back from Midas.
Unlock all lore.
Have 12 Disciples.
Unlock all outfits.
Completely Upgrade the Temple.
Hatch 5 eggs.