Here is the full list of all 41 Pentiment achievements.
Get Martin killed.
Get Hanna killed.
Get Lucky executed.
Get Matilda executed.
End Act I in the abbot's favor.
Get Ottilia executed.
Finished Act 3.
Cut enough cookies for everyone at the Christmas feast.
Learn the mystery of the cats.
Get assistance climbing down the mine shaft.
Learn about Artemis and Apollo's frog plan.
Examine 10 flowers.
Finished Act 2.
Get Aedoc his medicine.
Refuse to shoot at the deer.
Shoot the deer.
Get Guy killed.
Do your penance.
Discover the imposter.
Get knocked out.
Win everyone's money at Lansquenet.
Lose everything at Lansquenet.
Convince Endris to find his sweetheart.
Complain to Niko about your room.
Finished Act 1.
End Act I out of the abbot's favor.
Get Ferenc executed.
Pass 5 dialogue checks.
Tell Jacob Estler immaterial gossip.
Convince Jacob Estler to save Ottilia's home.
Pet 5 animals.
Headbutt Werner.
Spin wool as fast as the ladies.
Get Wojslav to let you into the cellar.
Convince Gernot to let you dig up the grave.
Have your hat stolen.
Seduce Zdena.
Solve Ferenc's cipher with the volvelle.
Encourage Paul to draw.
Find the secret door to library.
Convince Illuminata to give you the French book.