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