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