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