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