Here is the full list of all 32 Knights of the Rogue Dungeon achievements.
Defeat Tutorial level.
Defeat Dank Dungeon.
Defeat Graveyard.
Defeat Demon Knight I.
Defeat Ice Dungeon.
Defeat Frost Blight.
Defeat Demon Knight II.
Defeat Lava Dungeon.
Defeat Fiery Planes.
Purchase First Lucky Charm (20%).
Purchase Last Lucky Charm (100%).
Purchase First Death Tax (40%).
Purchase Last Death Tax (0%).
Purchase First Knight Power (7).
Purchase Last Knight Power (3).
Purchase First Invincible Armor.
Purchase First Extra Life.
Purchase First Vanquish Spell.
Achieve high score of 20,000 or more.
Defeat Demon Knight III with Sir Redmoor.
Defeat Demon Knight III with Lady Steadfast.
Defeat Demon Knight III with Max.
Defeat Demon Knight III with Totes.
Defeat Demon Knight III with Sir Skullahad.
Defeat Demon Knight III with Sir Blobcelot.
Defeat 10 Zombies.
Defeat 10 Skulls.
Defeat 10 Ghosts.
Defeat 10 Jacks.
Defeat 10 Red Devils.
Defeat 10 Demon Knights.
Start from Dank Dungeon and defeat Demon Knight III