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