Full list of all 29 Nightmares from the Deep 2: The Sirens Call achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
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.
Find all secret seahorses.
Complete the game.
Got to the contents of Davy Jones' chest.
Gather twelve golden fish tokens.
Finished all the puzzles without using the Skip button.
Finished all Hidden Object Puzzles.
Got to the top of the lighthouse and saw what's underneath.
Enabled your ally to return to work.
Prepare a spiked coffee.
Finished a Hidden Object Puzzle in less than 1 minute.
Found your way inside the lighthouse.
Finished 10 Hidden Object Puzzles in a row without any hints.
Find 4 Hidden Objects within 4 seconds.
Fix the radio.
Enter the shipwreck cemetery.
Tried to get through the labyrinth without the map.
Saved your ally from a tight spot.
Visited a local bar.
Find a direct way to get behind the closed gates.
Finished 5 puzzles in a row without using the Skip button.
Finish any Hidden Object scene with less than 3 misclicks.
Finished a puzzle in less than 1 minute.
Witnessed the devastating attack of the sea monster.
Arrived on the pier.