Full list of all 46 Slay the Spire achievements. It takes around 60-80 hours to unlock all of the achievements in the base game on Windows.
The base game contains 26 achievements, and there are 8 DLC packs containing 20 achievements.
Defeat a boss in a single turn.
Have 3 or fewer cards in hand, draw, and discard pile combined.
Play 10 Shivs in a single turn.
Have 999 Block during combat.
Beat the game with the Ironclad.
Have 50 or more Strength during combat.
Have 10 or more buffs during combat.
Play 25 cards in a single turn.
Defeated Donu & Deca.
Have 9 Energy during a single combat.
Defeated the Awakened One.
Beat the game with the Silent.
Apply 99 or more Poison on a single enemy.
Exhaust 20 cards in a single combat.
Defeated the Time Eater.
Have 99 or more Block during combat.
Defeat 3 enemies with Poison in a single combat.
Defeated the Bronze Automaton.
Win a battle with 1 HP remaining.
Defeated the Collector.
Win a combat without playing an Attack.
Defeat a boss without taking any damage.
Defeated the Slime Boss.
Defeated Hexaghost.
Defeated the Champ.
Defeated the Guardian.
Obtain all other Achievements.
Beat the game with a single relic.
Beat the game with a 5 card deck or smaller.
Beat the game in under 20 minutes.
Finish Donu with a Feed.
Complete Ascension Level 10.
Unlock Ascension mode.
Beat the game with a deck of only common cards.
Have 25 or more Focus during combat.
Beat the game with the Defect.
Channel 9 Plasma in a single turn.
Win a Daily Climb.
Defeat the Transient before it fades away.
Complete Ascension Level 20.
Complete the Ending with the Watcher.
Beat the game with the Watcher.