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