Here is the full list of all 27 Solitairica achievements.
Buy every spell in the game
Buy every item in the game
Fill the bar for all energy types.
Buy all 3 potions in a single journey
Encounter all enemy traits
Defeat Emperor Stuck
Enter Castle Stuck
Battle all 18 enemy types
Visit the Cliffs of Mythos
Unlock a second deck
Defeat the enemy without using any spells
Upgrade your first card in any deck
Visit Tangleslime Swamp
Visit the Ruinous Bog
Cause the enemy to sacrifice the last card
Visit the Blandlands
Match every numeral in a single streak
Break your heart by taking fatal damage on the last card
Start a new journey after your heart breaks the first time
Have your heart broken
Match 10 cards in a row
Visit the Meadows of Madness
Collect a wildstone from a card
Unlock the Warrior deck
Collect 50+ coins from a single card
Use Cosmic Inversion to go from 1 health to full
Defeat Emperor Stuck with every deck