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