Here is the full list of all 69 Diehard Dungeon achievements.
Attain Diehard rank.
Destroy 20 chests.
Defeat Giant Oaf.
Attain Legend rank.
Obtain Toasty ability.
Obtain Looter ability.
Attain Champion rank.
Defeat Zombie Chest.
Attain Hero rank.
Obtain Pierce ability.
Obtain Slash ability.
Avoid picking up 20 hearts.
Obtain Courage ability.
Obtain Repel ability.
Achieve rank 10 in Mayhem.
Defeat Mr Illusion.
Attain Slayer rank.
Defeat 2000 enemies.
Pickup 100 hearts.
Obtain Fireproof ability.
Attain Adept rank.
Use 50 tokens.
Destroy 300 lights.
Destroy 1000 containers.
Obtain Reflex ability.
Defeat Evil Chest.
Obtain Forget-Me-Not ability.
Have 20 tokens.
Attain Valiant rank.
Escape the dungeon.
Open the gold chest.
Defeat Hive Mind.
Attain Warrior rank.
Collect 10,000 treasure.
Obtain Lightfoot ability.
Obtain Scatter ability.
The Companion Chest upgrades to its maximum level.
Obtain Iron Grip ability.
Obtain Triple Shot ability.
Obtain Heartbreaker ability.
Attain Fighter rank.
Obtain Heavy Duty ability.
Obtain Sense ability.
Obtain Knives ability.
Obtain Vision ability.
Defeat the Dungeon Master.
Escape the dungeon in Champion Mode.
Win a Trapdoor game.
Use 20 Teleporters.
Obtain Houdini ability.
Obtain Dash ability.
Obtain Kaboom ability.
Obtain Voodoo ability.
Obtain Mithridate ability.
Obtain Trigger Happy ability.
Defeat Stumpy.
Avoid opening 10 chests.
Defeat 200 enemies by setting them on fire.
Destroy 500 containers with fire.
Survive 20 rooms of Survival
Obtain Attract ability.
Escape the dungeon at Diehard rank, in Champion Mode, and defeat the Dungeon Master.
Complete Fading Light in under 3 minutes.