Here is the full list of all 38 Ziggurat achievements.
Unlock all character classes
Unlock all amulets
Win the game without using any level up
Kill 5000 enemies
Find a super secret cheat code
Unlock all enemies in the bestiary
Break 2,000 things (Barrels, tombs...)
Kill a Lost soul with the Skull of Xanatos
Find all lore scrolls
Get to floor 3 using only the magic wand (Apprentice class only)
Kill 500 enemies affected with elemental states
Win the game with Argo on Normal difficulty in less than 45 minutes
You met your match in the final showdown
Kill all enemies at least once (including bosses)
Master a perk by getting it to level 5
Survive the Ziggurat
Reach experience level 15
Die 10 times
Complete a challenge room
Died after killing the boss
Kill 1000 enemies
Find your first amulet
Reach experience level 10
Equip a weapon of every kind
Find a secret room
Reach experience level 5
You've been ambushed in a treasure room
You reached 3rd floor. Now the real lesson begins.
Get your first level up
You died on a danger room
Unlock all magic weapons
Unlock all perks
Unlock all weapons,perks,lore & character classes
Die 25 times
Die 50 times
Reach floor 2 without getting damaged
Win a game with every character (any difficulty)
Win a game on hard difficulty