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