Here is the full list of all 35 One Step From Eden achievements.
Beat Hell Mode 14
Beat the game without collecting any Artifacts
Beat the game without taking any spells
Execute Serif
Defeat tier 4 Shopkeeper
Kill the last enemy with the Fadeaway spell
Beat the game with every character
Kill a hostage with the Devour spell
Cover the entire field in flames
Have 0 Max Mana
Have 8 pacts at the same time
Execute Terrable
Defeat tier 4 Selicy
Defeat tier 4 Saffron
Have over 200 cardtridges in your deck
Beat Serif and get sent back
Have at least 16 broken tiles at the same time
Have 1 Spell in your deck
Defeat tier 4 Violette
Defeat tier 4 Reva
Have over 9,999 Shield
Win a battle without using a Spell or Weapon
Cast 10 Jams in one battle
Defeat tier 4 Shiso
Upgrade the same spell 4 times
Win a boss fight with 1 HP
Kill Gunner or Shiso with a Slashfik spell
Reach the Gate
Defeat tier 4 Hazel
Destroy a Self Defense hazard
Spare Terrable
Defeat tier 4 Terra
Defeat tier 4 Gunner
Get a Calamity spell
Have a spell from every Focus in your deck