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