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