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