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