Full list of all 46 Slay The Spire achievements worth 1,070 gamerscore. It takes around 150-200 hours to unlock all of the achievements in the base game.
The base game contains 44 achievements worth 1,000 Gamerscore, and there is 1 DLC pack containing 2 achievements worth 70 Gamerscore.
Complete the Ending with the Defect.
Beat the game with the Silent.
Defeated the Time Eater.
Have 10 or more buffs during combat.
Have 99 or more Block during combat.
Win a Daily Climb.
Beat the game with the Defect.
Defeated Donu & Deca.
Win a battle with 1 HP remaining.
Have 9 Energy during a single turn of combat.
Win a combat without playing an Attack.
Exhaust 20 cards in a single combat.
Defeated the Collector.
Defeat 3 enemies with Poison in a single combat.
Unlock Ascension mode.
Beat the game with the Ironclad.
Defeated the Awakened One.
Defeated the Bronze Automaton.
Defeated the Slime Boss.
Defeat a boss without taking any damage.
Defeated Hexaghost.
Defeated the Champ.
Defeated the Guardian.
Complete Ascension Level 20.
Beat the game with a deck containing no uncommons or rares.
Beat the game with a single relic.
Have 25 or more Focus during combat.
Channel 9 Plasma in a single turn.
Complete the Ending with the Ironclad, Silent, and Defect.
Beat the game with a 5 card deck or smaller.
Complete the Ending with the Silent.
Complete the Ending with the Ironclad.
Defeat the Transient before it fades away.
Beat the game in under 20 minutes.
Finish Donu with a Feed.
Complete Ascension Level 10.
Defeat a boss on turn 1.
Have 999 Block during combat.
Play 10 Shivs in a single turn.
Play 25 cards in a single turn.
Have 50 or more Strength during combat.
Have 3 or fewer cards in hand, draw, and discard pile combined.
Apply 99 or more Poison on a single enemy.
Obtain all other Achievements
Beat the game with the Watcher
Complete the Ending with the Watcher