Here is the full list of all 27 Ruin Raiders achievements.
Complete the Tutorial
Defeat 'The Guardian'
Defeat 'The Crusher'
Defeat 'The Corrupted'
Complete the game
Unlock Cats
Unlock Salamanders
Unlock Walruses
Spend 5000 Entium in the shop
Spend 15000 Entium in the shop
Spend 100000 Entium
Spend 500000 Entium
Kill 100 enemies
Kill 500 enemies
Lose a run
Win a battle in your first round
Upgrade all buildings to the maximum level
Equip a Demon weapon
Activate the mastery that upgrades your skill
Activate all of the masteries of a single Raider
Collect all text fragments of a single book
Collect all text fragments
Craft 50 pieces of equipment
Craft 100 pieces of equipment
Enter a shop
Solve one type of puzzle door
Complete all achievements