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