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