Here is the full list of all 15 A Legend of Luca achievements.
Reach Level 5
Reach Level 4
Reach Level 3
Reach Level 2
Defeat Vulcan, God of Fire
Complete 5 Runs... Win or Lose
Find All Weapons of Virtue
Win the Game as a Paladin
Win the Game as a Shaman
Win the Game as a Dragon Trainer
Win the Game as a Grenadier
Win the Game as a Death Knight
Win the Game with Rhaegos at Your Side
Win the Game as a Mercenary
Win the Game as a Harbinger Of Death