Here is the full list of all 15 Nightmares from the Deep: The Cursed Heart achievements worth 1,000 gamerscore.
Ye barely made a mistake! Yer clickin’ hook’s as steady as they come.
Seems “3” is yer lucky number, ‘ey, matey!
Three without reshuffling! An admirable job!
Three games and nay skips—The odds certainly be in yer favour now!
Impressive work, matey, ye finished that game in under a minute!
Complete the game (Normal Difficulty).
Finish any Hidden Object scene in less than 1 minute.
Finish half of all the games of Mah-jong.
Finish all the games of Mah-jong.
Finish all mini-games without using the ‘SKIP’ option.
Complete the game (Expert Difficulty).
Finish all Hidden Object scenes without using any hints.
Finish a game of Mah-jong in less than 1 minute.
Collect all the Cursed Coins.
Complete the Bonus Chapter (Any Difficulty).