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