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.
Unlock all fleeces.
Defeat the One Who Waits.
Beat Shamura without taking damage.
Beat Kallamar without taking damage.
Beat Heket without taking damage.
Reignite the lighthouse.
Beat Leshy without taking damage.
A deal that cannot be undone.
Unlock all Follower Skins.
Catch 1 of every fish.
Unlock all tarot cards.
Defeat all opponents in Knucklebones.
Defeat Shamura.
Find all 5 locations.
Cook a Follower meat meal.
Defeat Kallamar.
Sacrifice a Follower.
Win a game of Knucklebones.
Take confession.
Unlock a new fleece.
Gain 20 Followers.
Defeat Leshy.
Unlock all curses.
Have 666 gold coins.
Defeat Heket.
Unlock all weapons.
Unlock all doctrines.
Defeat the first mini-boss.
Fully Upgrade Cult.
A new world awaits.
Let the Word be known.
Salvation awaits the fallen soul.
The first devotee to the Cult of the Lamb.
Gain 5 Followers.
Gain 10 Followers.
No longer a servant, no less than a God.
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.