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