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