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