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.
Catch 1 of every fish.
Take confession.
Cook a Follower meat meal.
Unlock all curses.
Defeat the One Who Waits.
Unlock all weapons.
Gain 20 Followers.
Defeat Shamura.
Defeat all opponents in Knucklebones.
Have 666 gold coins.
Find all 5 locations.
Defeat Kallamar.
Unlock all doctrines.
Fully Upgrade Cult.
Defeat Heket.
Win a game of Knucklebones.
Unlock a new fleece.
Reignite the lighthouse.
Gain 10 Followers.
The first devotee to the Cult of the Lamb.
Gain 5 Followers.
Defeat the first mini-boss.
A new world awaits.
Sacrifice a Follower.
Salvation awaits the fallen soul.
Let the Word be known.
Defeat Leshy.
Beat Leshy without taking damage.
A deal that cannot be undone.
Beat Heket without taking damage.
Beat Kallamar without taking damage.
Beat Shamura without taking damage.
Unlock all Follower Skins.
Unlock all tarot cards.
Sacrifice 10 Followers.
Unlock all fleeces.
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.