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