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