Here is the full list of all 31 Nightmares from the Deep 2: The Siren's Call trophies - there are 14 bronze, 10 silver, 6 gold and 1 platinum.
Unlock every Trophy.
Finish all the games of Mahjong.
Find all morphing parrots.
Finish a game of Mahjong in less than 1 minute.
Finish half of all the games of Mahjong.
Find all hidden octopi.
Finish 10 Hidden-Object Scenes in a row without using any hints.
Find all secret sea horses.
Complete the bonus adventure.
Complete the game.
Complete the game on expert difficulty.
Get to the contents of Davy Jones' chest.
Gather twelve golden fish tokens.
Finish all the puzzles without skipping.
Finish all Hidden-Object Scenes.
Get to the top of the lighthouse and see what's underneath.
Enable your ally to return to work.
Prepare a spiked coffee.
Find your way inside the lighthouse.
Fix the radio.
Enter the shipwreck cemetery.
Find 4 Hidden Objects within 4 seconds.
Save your ally from a tight spot.
Find a direct way to get behind the closed gates.
Finish 5 puzzles in a row without skipping.
Finish a Hidden-Object Scene in less than 1 minute.
Visit local bar.
Finish any Hidden Object scene with less than 3 mistakes.
Finish a puzzle in less than 1 minute.
Witness the devastating attack of the sea monster.
Arrive on the pier.