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.
Beat Kallamar without taking damage.
Beat Heket without taking damage.
Unlock all fleeces.
Unlock all tarot cards.
Unlock all Follower Skins.
Defeat the One Who Waits.
Defeat all opponents in Knucklebones.
Defeat Shamura.
Beat Shamura without taking damage.
Find all 5 locations.
Sacrifice a Follower.
Defeat Kallamar.
Beat Leshy without taking damage.
Have 666 gold coins.
Catch 1 of every fish.
Take confession.
Unlock all weapons.
Gain 20 Followers.
Reignite the lighthouse.
Defeat Heket.
Unlock all doctrines.
Unlock all curses.
Fully Upgrade Cult.
Gain 10 Followers.
Cook a Follower meat meal.
Unlock a new fleece.
Salvation awaits the fallen soul.
Defeat Leshy.
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 outfits.
Unlock all lore.
Completely Upgrade the Temple.
Hatch 5 eggs.
Have 12 Disciples.