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