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