Here is the full list of all 26 Deathtrap Dungeon Trilogy achievements.
Complete Armies of Death on Adventurer difficulty
Complete Deathtrap Dungeon
Complete 8 quests in any one book
Pass 20 Skill Tests
Defeat the Bloodbeast in Deathtrap Dungeon
Complete the first trial in Deathtrap Dungeon
Correctly answer two or more riddles in Deathtrap Dungeon
Find and rescue the prisoner in Deathtrap Dungeon
Solve the Port Blacksand murder mystery
Complete Armies of Death on Hero difficulty
Complete Armies of Death on Legend difficulty
Complete the Creature Codex
Pass 20 Luck Tests
Unlock all Titles
Fully upgrade all Skill dice
Fully upgrade all Luck dice
Hire an army to save the world
Destroy Agglax the Shadow Demon
Tell Baron Sukumvit what happened to his Nandibear
Visit the Oracle
Find all of the Gold Rings in Trial of Champions
Walk through fire unharmed
Complete the first trial in Trial of Champions
Win 5 Skirmish Battles
Win the pie eating competition
Travel to Zengis by boat