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