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