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