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