Here is the full list of all 51 The Bard's Tale achievements.
Defeated the rats in the cellar
Learned the song of the Thunder Spider
Used Caleigh's Artifact to summon Caleigh
Used Herne's Artifact to summon Herne
Used Lugh's Artifact to summon Lugh
Used Mannanan's Artifact to summon Mannanan
Learned the song of the Mercenary
Learned the song of the Knight
Learned the song of the Heroine
Learned the song of the Brute
Learned the song of the Elemental
Learned the song of the Behemoth
Learned the song of the Knocker
Learned the song of the Crone
Learned the song of the Enchantress
Learned the song of the Bodyguard
Learned the song of the Rogue
Learned the song of the Explorer
Learned the song of the Gouger
Learned the song of the Light Fairy
Finished Chapter 1: Houton
Finished Chapter 2: Neversdale Forest
Finished Chapter 3: Kirkwall
Finished Chapter 4: Highland Park
Finished Chapter 5: The Forest Tower
Finished Chapter 6: The Mountain Pass
Finished Chapter 7: The Mountain Tower
Finished Chapter 8: Dounby
Finished Chapter 9: Finstown
Finished Chapter 10: Greenlands
Finished Chapter 11: Stromness
Finished Chapter 12: The Firbolg Mines
Finished Chapter 13: The Island Tower
Finished the game on Easy Mode
Finished the game on Normal Mode
Finished the game on Olde School Mode
Collected the Ratty Old Map from the Wandering Trow to unlock secret area
Collected the Ancient Parchment Map from the Wandering Trow to unlock secret area
Collected the Weather Stained Map from the Wandering Trow to unlock secret area
Collected the Blood Stained Map from the Wandering Trow to unlock secret area
Collected 5 tokens
Collected 10 tokens
Collected 20 tokens
Killed 30 chickens
Tipped 30 Cows
Hunted 1 grouse
Defeated the Bugbear of Houton
Donated 20,000 silver at the Kirks (churches)
Talked to Roxy the dog
Drank 1 beverage in each of the 5 bars: The Drunken Rat, The Aiken Drum, Trowies Pub, The Fat Lute, and The Tup
Participated in the talent show in Dounby