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.
Finished all Hidden Object Puzzles.
Finished 10 Hidden Object Puzzles in a row without any hints.
Finish any Hidden Object scene with less than 3 misclicks.
Finished a Hidden Object Puzzle in less than 1 minute.
Find 4 Hidden Objects within 4 seconds.
Complete the game.
Got to the contents of Davy Jones' chest.
Find all morphing parrots.
Find all secret seahorses.
Find all hidden octopi.
Gather twelve golden fish tokens.
Finished all the puzzles without using the Skip button.
Got to the top of the lighthouse and saw what's underneath.
Enabled your ally to return to work.
Prepare a spiked coffee.
Found your way inside the lighthouse.
Finish half of all the games of Mahjong.
Fix the radio.
Enter the shipwreck cemetery.
Tried to get through the labyrinth without the map.
Saved your ally from a tight spot.
Find a direct way to get behind the closed gates.
Finish a game of Mahjong in less than 1 minute.
Finished 5 puzzles in a row without using the Skip button.
Visited a local bar.
Finished a puzzle in less than 1 minute.
Witnessed the devastating attack of the sea monster.
Arrived on the pier.