Here is the full list of all 15 Heroic Dungeon achievements.
Destroy 50000 monster heads
Kill 1000 enemies
Complete 100 dungeons
Destroy 5000 monster heads
Complete 25 bonus levels
Kill 100 enemies
Upgarde 3 items
Find 25 swords
Find 25 hearts
Complete 10 dungeons
Find 25 chests
Complete 5 bonus levels
Destroy 500 monster heads
Kill 10 enemies
Complete 1 dungeon