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.
Unlock all fleeces.
No longer a servant, no less than a God.
Sacrifice 10 Followers.
Catch 1 of every fish.
Beat Leshy without taking damage.
Unlock all Follower Skins.
Defeat the One Who Waits.
Defeat Shamura.
Beat Shamura without taking damage.
Unlock all tarot cards.
Defeat all opponents in Knucklebones.
Find all 5 locations.
Defeat Kallamar.
Beat Kallamar without taking damage.
Unlock all weapons.
Gain 20 Followers.
Unlock all curses.
Unlock all doctrines.
Fully Upgrade Cult.
Have 666 gold coins.
Defeat Heket.
Beat Heket without taking damage.
Take confession.
Unlock a new fleece.
Gain 10 Followers.
Reignite the lighthouse.
Defeat Leshy.
Win a game of Knucklebones.
Cook a Follower meat meal.
Gain 5 Followers.
A new world awaits.
Sacrifice a Follower.
Salvation awaits the fallen soul.
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.
Collect all Relics.
Get your Gold back from Midas.
Complete a row in Purgatory.
Unlock all lore.
Unlock all outfits.
Have 12 Disciples.
Completely Upgrade the Temple.
Hatch 5 eggs.