Here is the full list of all 37 Salt and Sanctuary achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Discover your first brand.
Defeat the Kraekan Cyclops.
Defeat the Queen of Smiles.
Defeat the Mad Alchemist.
Take an oath to The Stone Roots.
Take an oath to Devara's Light.
Defeat the Sodden Knight.
Claim your first sanctuary.
Take an oath to The Three.
Defeat the Unspeakable Deep.
Aid a despondent thief.
Aid a questing knight.
Aid an unraveling sorceror.
Bear all possible brands.
Take an oath to The Iron Ones.
Take an oath to the gods of Fire and Sky.
Take an oath to The House of Splendor.
Take an oath to the Order of the Betrayer.
Achieve the maximum devotion level in your creed.
Achieve the maximum upgrade level of a weapon.