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.
Take an oath to The Iron Ones.
Discover your first brand.
Take an oath to The Stone Roots.
Defeat the Mad Alchemist.
Defeat the Kraekan Cyclops.
Defeat the Queen of Smiles.
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 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.