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.
Beat Shamura without taking damage.
Sacrifice 10 Followers.
No longer a servant, no less than a God.
Unlock all Follower Skins.
Beat Leshy without taking damage.
Beat Heket without taking damage.
Defeat the One Who Waits.
Gain 20 Followers.
Unlock all fleeces.
Defeat Shamura.
Unlock all tarot cards.
Take confession.
Defeat all opponents in Knucklebones.
Find all 5 locations.
Unlock all weapons.
Defeat Kallamar.
Have 666 gold coins.
Unlock all curses.
Fully Upgrade Cult.
Unlock all doctrines.
Gain 10 Followers.
Catch 1 of every fish.
Defeat Heket.
Unlock a new fleece.
Cook a Follower meat meal.
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.
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.