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.
Have 999 Block during combat.
Have 99 or more Block during combat.
Have 50 or more Strength during combat.
Play 25 cards in a single turn.
Play 10 Shivs in a single turn.
Win a combat without playing an Attack.
Have 10 or more buffs during combat.
Defeated Donu & Deca.
Exhaust 20 cards in a single combat.
Have 9 Energy during a single combat.
Defeated the Slime Boss.
Defeated the Bronze Automaton.
Beat the game with the Silent.
Defeated the Time Eater.
Apply 99 or more Poison on a single enemy.
Win a battle with 1 HP remaining.
Defeated the Collector.
Defeat 3 enemies with Poison in a single combat.
Defeated Hexaghost.
Beat the game with the Ironclad.
Defeated the Awakened One.
Defeat a boss without taking any damage.
Defeated the Champ.
Defeated the Guardian.
Obtain all other Achievements.
Beat the game with a 5 card deck or smaller.
Beat the game with a single relic.
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.