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