Here is the full list of all 32 Stirring Abyss achievements.
Detonate the Soviet nuclear bomb.
Defeat the Captain Ascendant.
Uncover 1,000 Clues.
Defeat the Gatekeeper.
Pump every section of the Salem.
Have a single diver undergo four Mutations.
Recover the arming code for the Soviet nuclear bomb.
Unlock one of the top-level nodes on the Eldritch track of the Enigma Board.
Inspect a dead Soviet Diver.
Defeat the First to Hunger.
Inspect a dead Stalking Tentacle.
Kill five or more enemies in a single turn.
Unlock one of the top-level nodes on the Mechanical track of the Enigma Board.
Inspect a dead Harvester.
Inspect a dead Fathom Seer.
Deal 250 damage to enemies in a single turn.
Mutate one of your divers.
Have an enemy kill another enemy.
Inspect a dead Scyphozoa.
Inspect a dead Spineskulker.
Inspect a dead Murkfiend.
Inspect a dead Burst Pod.
Inspect a dead Infected Pod.
Inspect a dead Vessel.
Inspect a dead Voidspawn.
Complete the game on Hard difficulty.
Earn 20,000 score on Endless Mode.
Kill 500 enemies.
Kill one of your divers with friendly fire.
Unlock one of the top-level nodes on the Biological track of the Enigma Board.
Use the Profane Chapel to resurrect a dead diver.
Deal 150 damage with one critical attack.