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