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