Here is the full list of all 30 Nightmares from the Deep 3: Davy Jones achievements worth 1,000 gamerscore.
Finish 3 Hidden Object Puzzles by playing Mahjong.
Complete the game on expert difficulty.
Complete the game.
Cancel all of the pacts.
Finish all Puzzles without using the Skip Button.
Find all of the hidden puzzle pieces.
Find all the glowing seahorses.
Find all of the Pirate Cards.
Interact with 16 Animals on the Island.
Listen to all of the Guardians’ stories.
Finish all Hidden Object Puzzles without using hints.
Open the Forbidden Gate.
Brew O’Malley's potion.
Get the witch to help you.
Find the hint about the treasure of Davy Jones.
Get to O’Malley’s Hideout.
Reconnect with Cory.
Finish 6 Hidden Object Puzzles in a row without using hints.
Finish any Hidden Object Puzzle in less than 1 minute.
Finish any Hidden Object scene with less than 4 mistakes.
Find out what Davy Jones is hiding in the Icehouse.
Find out how to cancel the pact.
Get to the prison cell.
Complete 3 Puzzles without using the Skip Button.
Find 5 hidden objects within 5 seconds.
Find the first Pirate Card.
Find a glowing seahorse.
Interact with 3 Animals on the Island.
Find the first hidden puzzle piece.
Escape from the cell.