Here is the full list of all 38 Ziggurat achievements.
Unlock all perks
Unlock all weapons,perks,lore & character classes
Get to floor 3 using only the magic wand (Apprentice class only)
Die 25 times
Unlock all magic weapons
Unlock all amulets
Win the game with Argo on Normal difficulty in less than 45 minutes
Unlock all character classes
Find all lore scrolls
Kill all enemies at least once (including bosses)
Unlock all enemies in the bestiary
Kill 5000 enemies
Break 2,000 things (Barrels, tombs...)
Kill a Lost soul with the Skull of Xanatos
Find a secret room
Die 10 times
Kill 500 enemies affected with elemental states
Survive the Ziggurat
Equip a weapon of every kind
You met your match in the final showdown
Master a perk by getting it to level 5
Kill 1000 enemies
Reach experience level 15
Reach experience level 10
You reached 3rd floor. Now the real lesson begins.
Reach experience level 5
You've been ambushed in a treasure room
You died on a danger room
Find your first amulet
Complete a challenge room
Get your first level up
Find a super secret cheat code
Die 50 times
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