Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Get all collectibles.
Achieve the maximum value of flasks.
Achieve the maximum value of fervor.
Bring all the offerings to Lvdovico.
Achieve the maximum value of rosary bead slots.
Help Cleofás in his path of redemption.
Release all cherubs.
Visit the tomb of The Lady of the Tailed Gown.
Achieve the maximum level of the Mea Culpa sword.
Talk with all the corpses.
Get all relics.
Bring all the offerings to the Blessed Lord of Salty Shores.
Help the Pilgrim reach his final destination.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Save all Kissers of Wounds.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Beat all types of enemies.
Buy all the items of the Candelaria shops.
Beat Melquíades, The Exhumed Archbishop.
Beat Exposito, Scion of Abjuration.
Beat Esdras, of the Anointed Legion.
Hatch the Egg of Altasgracias.
Beat the Our Lady of the Charred Visage.
Kill 666 enemies.
Beat the Tres Angustias.
Execute 5 different enemies.
Beat Perpetua.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.
Beat His Holiness Escribar.
Unlock the ending A.
Unlock the ending B.
Beat all the arena challenges.
Get all prayers.
Get all rosary beads.
Get all sword hearts.
Use the Righteous Riposte 5 times.
Witness the last moments of Viridiana.
Buy all skills from the Mea Culpa shrines.
Provoke the meeting between Redento and Cleofás.
Beat all bosses without flask consumption.
Cross the Bridge door in less than 3 hours.
Get 100% of the game.