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