Here is the full list of all 15 bit Dungeon II achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Enter into the Dark World.
Free the ghost from her grave.
Slayed the Fiend.
Face The Eater!
Slay the Demiurge.
Tis this a demon?
Kill the leader of the Thief Kings, The Cursed Wizard!
Destroy the Soul Collector.
Kill the king of Skeletons.
Slay the Fire Nob Glob.
Find an epic-quality weapon.
You have died. You have all lost things. You can not take your possessions with you to the next incarnation.
She rules an army of beasts in the Black Church, defeat The Yaldabaoth.
Kill a mini-boss.
Reach level ten.