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.
Play 10 Shivs in a single turn.
Play 25 cards in a single turn.
Have 3 or fewer cards in hand, draw, and discard pile combined.
Have 10 or more buffs during combat.
Have 999 Block during combat.
Have 99 or more Block during combat.
Have 50 or more Strength during combat.
Win a battle with 1 HP remaining.
Defeated Donu & Deca.
Win a combat without playing an Attack.
Apply 99 or more Poison on a single enemy.
Defeat 3 enemies with Poison in a single combat.
Beat the game with the Silent.
Defeated the Time Eater.
Have 9 Energy during a single combat.
Defeated the Bronze Automaton.
Beat the game with the Ironclad.
Defeated the Awakened One.
Defeated the Collector.
Defeated the Slime Boss.
Exhaust 20 cards in a single combat.
Defeat a boss without taking any damage.
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.
Finish Donu with a Feed.
Beat the game in under 20 minutes.
Complete Ascension Level 10.
Unlock Ascension mode.
Have 25 or more Focus during combat.
Beat the game with a deck of only common cards.
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.