Here is the full list of all 55 Dragon of Steelthorne achievements.
Complete the tutorial.
Hold the line against a horde of barbarians.
Get overwhelmed by a horde of barbarians.
Trick the wildmen into leaving.
Defeat the Nian.
Survive the river on your first attempt.
Lose the battle of Huolong.
Win the battle of Huolong.
Side against His Majesty after an act of treachery.
Learn the secret of the Dragon Gem from Lavina.
Pay for Montague's men up front.
Encounter the Wyvern's regenerative ability.
Defeat the Wyvern.
Resolve Pretessa Cora's mission peacefully.
Correctly answer all Basil's riddles.
Correctly answer all Basil's puzzles.
Defeat the Gray Horses.
Attempt all side missions.
Attend the Eternal Festival.
Duel Lord William as a paladin.
Watch a play.
Draw a picture.
Save your game.
Construct the Cathedral.
Construct the Train Station.
Complete all construction projects.
Reach a population of 10,000.
Reach a resource level of 5000.
Reach a prosperity level of 70.
Reach a contentment level of 70.
Reach a high relationship level with Rosie.
Reach a high relationship level with Lord Hugo.
Reach a high relationship level with Chang.
Reach a high relationship level with Lady Anne.
Reach a high relationship level with Alicia.
Romance Lord Hugo.
Romance Chang.
Romance Lady Anne.
Romance Alicia.
Romance Princess Bridget.
Hand the Dragon Gem to His Majesty.
Escape from Lake Steelthorne using the Dragon Gem.
Protect Lake Steelthorne using the Dragon Gem.
Infuse yourself with the power of the Dragon Gem.
Complete the story as a paladin.
Complete the story as a surgeon.
Complete the story as an engineer.
Complete the story as a trader.
Complete the story as a historian.
Complete the story without starting any romances.
Complete the story without fighting any battles.
Complete the story on the God Mode difficulty setting.
Complete the story on the Hard difficulty setting.
Complete the story on the Brutal difficulty setting.
Reach the Secret Ending. Good luck with that!