Here is the full list of all 29 Project Abyss achievements.
Be underwater for 10 days.
Deploy a drone to help you collect loot.
Leave the submarine.
Chain hook the submarine.
Discover all friendly sea creatures.
Discover all vicious sea creatures.
Complete the tutorial.
Complete area A.
Complete area B.
Compelete area C.
Complete area D.
Enter the deep trench.
Defeat the creature.
Destroy The Swarm.
Defeat The Ripper.
Defeat The Tank.
Destroy the Command Centre and open the door.
Collect poison.
Defeat a Whale.
Collect 10,000 pounds.
Collect a great chest.
Watch a sun-rise.
Return to the submarine with less than 10 oxygen left.
Refill the submarine with less than 10 fuel left.
Unlock the Survival Submarine.
Unlock the Attack Submarine.
Unlock the Defence Submarine.
Find the skeleton.
Complete the game.