Here is the full list of all 36 TUNIC achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Had 10 moneybanks at once
Found a certain weapon before getting a sword. (Page 38)
Made 15 wishes
Found your rightful place
Found Secret Treasure #11
Found Secret Treasure #10
Found Secret Treasure #2
Found Secret Treasure #5
Completed the Manual
Found Secret Treasure #7
Found Secret Treasure #6
Freed a friendly fairy
Restored corporeal form
Found Secret Treasure #12
Found Secret Treasure #9
Found Secret Treasure #4
Found Secret Treasure #3
Found Secret Treasure #8
Earned the Cathedral's Prize
Completed key collection
Found the green key
Found the blue key
Froze yourself
Found the red key
Engaged a strange device
Found Secret Treasure #1
Rang the Western Bell
Chopped down 1000 blades of grass
Understood the margin of page 17
Made a wish
Made an offering
Perfectly executed a special technique
Rang the Eastern Bell
Was resurrected
Found a sword
Found a stick