Here is the full list of all 15 Heroes of Loot achievements.
Buy a titanium shield
Reach dungeon level 15
Get the "Lens of secret"
Kill a cyclops
Save a lost soul
Become invisible
Upgrade the difficulty of the dungeon
Play in the Arena room
Activate a statue
Drink from the well
Become level 10
Slay 5000 monsters
Kill a minotaur
Maximise dungeon difficulty
Unlocked Barbarian character