Here is the full list of all 59 The Bard's Tale IV: Directors Cut achievements.
Save the world
Complete the final dungeon
Have a Rogue attain the Thief class
Kill Bishop Henred
Have a Rogue attain the Saboteur class
Defeat Tarjan
Defeat Lagoth Zanta
Hoard 10,000 gold
Clear the Stronsea Isles of Miasma
Have a Bard attain the Brewmaster class
Reach level 20
Defeat Mangar
Have a Bard attain the Troubadour class
Have a Bard equipped with both the Jesters Shoes and Jesters Cap
Reach level 18
Find the Strifespear
Slay a corrupt paladin
Have a Bard attain the Minstrel class
Have a Practitioner attain the Sorcerer class
Have a Fighter attain the Defender class
Clear the corruption in the Forest of the Inchriach
Have a Fighter attain the Vanguard class
Have a Fighter attain the Veteran class
Have a Rogue attain the Assassin class
Have a Bard attain the Rabble-Rouser class
Slay a paladin
Defeat Gaufroi
Reach level 10
Uncover the secret of sinister street
Have a Practitioner attain the Conjurer class
Discover the gloves of the dead mage's apprentice
Defeat the wraith of Mangar
Use standing stones for the first time
Hire a mercenary
Craft your first item
Pray to an Altar of Gratitude
Create a Bard as your starting character
Keep Melody as your starting character
Create a Fighter as your starting character
Create a Practitioner as your starting character
Create a Rogue as your starting character
Unlock the secrets of a code wheel statue
Find the Spectre Snare
Find the Destiny Wand
Defeat the final boss with only 3 party members
Summon a Pillar of Flame
Unlock the magic within a puzzle weapon's pommel
Unlock the magic within a puzzle weapon's grip
Unlock the magic within a puzzle weapon's hilt
Have a Fighter attain the Champion class
Have a Fighter attain the Commander class
Have a Practitioner attain the Archmage class
Have a Practitioner attain the Magician class
Have a Practitioner attain the Wizard class
Have a Rogue attain the Shadow class
Have a Rogue attain the Dirty Fighter class
Have a Bard attain the War Chanter class
Have an adventurer attain the Saint class
Put King Gaerwyn to rest and restored peace in the Haernhold