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.
Achieve the maximum upgrade level of a weapon.
Take an oath to the Order of the Betrayer.
Take an oath to the gods of Fire and Sky.
Aid a questing knight.
Bear all possible brands.
Take an oath to The House of Splendor.
Aid a despondent thief.
Take an oath to The Iron Ones.
Defeat the Kraekan Cyclops.
Defeat the Queen of Smiles.
Discover your first brand.
Defeat the Mad Alchemist.
Take an oath to The Stone Roots.
Take an oath to The Three.
Defeat the Sodden Knight.
Claim your first sanctuary.
Take an oath to Devara's Light.
Defeat the Unspeakable Deep.
Aid an unraveling sorceror.
Achieve the maximum devotion level in your creed.