Here is the full list of all 32 The Count Lucanor achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Find the chest hidden near your house.
Find some stale bread before night falls.
Find the castle's wall at day.
Find J.F.'s most important note.
Enter the fire room from a secondary door.
Use the snake ring at the best place.
Catch Eisbein.
Kill the old woman and Eisbein.
Guess the kobold's name without using the letters.
Open the garden chest.
Guess the kobold's name using the letters.
Feed the worm from the depths.
Catch the butterfly in the depths.
Discover the truth in the throne hall.
Find the hidden treasure of the Count.
Get the treasure hunter badge from Giulia.
Get the fire room letter without using the bucket of water.