Here is the full list of all 15 DRAGON: A Game About a Dragon achievements.
Complete the NPC's secret sidequest.
Finish the game with the best ending.
Defeat the king's bodyguards without taking damage.
Find the Stannum Sollerets and all five gemstones.
Find five very special treasures.
Trick a Lancer into dashing down a pit.
Have 10,000 gold at once without depositing it at home.
Learn to use Magic Breath.
Defeat Boudouin and Alex without taking damage.
Defeat the Bishounent without taking damage.
Defeat the Admiral without taking damage.
Defeat TM-061 without taking damage.
Get Dragon to whistle three particular songs.
Clear the game without increasing your HP from taking damage.
Finish the game with the regular ending.