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.
Use the Righteous Riposte 5 times.
Beat Perpetua.
Get 100% of the game.
Buy all skills from the Mea Culpa shrines.
Unlock the ending A.
Achieve the maximum value of rosary bead slots.
Beat all the arena challenges.
Get all rosary beads.
Get all prayers.
Get all sword hearts.
Bring all the offerings to Lvdovico.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Get all collectibles.
Release all cherubs.
Talk with all the corpses.
Achieve the maximum level of the Mea Culpa sword.
Achieve the maximum value of flasks.
Buy all the items of the Candelaria shops.
Help Cleofás in his path of redemption.
Save all Kissers of Wounds.
Unlock the ending B.
Beat His Holiness Escribar.
Beat Crisanta of the Anointed Blade.
Beat all types of enemies.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Achieve the maximum value of fervor.
Witness the last moments of Viridiana.
Beat Exposito, Scion of Abjuration.
Discover all zones.
Beat Melquíades, The Exhumed Archbishop.
Help the Pilgrim reach his final destination.
Beat Esdras, of the Anointed Legion.
Hatch the Egg of Altasgracias.
Beat the Tres Angustias.
Visit the tomb of The Lady of the Tailed Gown.
Kill 666 enemies.
Beat the Our Lady of the Charred Visage.
Execute 5 different enemies.
Beat Ten Piedad.
Beat the Warden of the Silent Sorrow.