Here is the full list of all 15 Nightmares from the Deep: The Cursed Heart achievements worth 1,000 gamerscore.
Ahoy! Ye bested the game, matey—Ye an old salt now!
Ho, matey! All those cursed coins are now yers. Nicely done!
All games won without a skip! Ye sure ye never played this before?
All o’ them without a hint? Guess ye ain’t the map-usin’ type...
Impressive work, matey, ye finished that game in under a minute!
Seems “3” is yer lucky number, ‘ey, matey!
Three games and nay skips—The odds certainly be in yer favour now!
Ye barely made a mistake! Yer clickin’ hook’s as steady as they come.
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.
Complete the game (Expert Difficulty).
Finish a game of Mah-jong in less than 1 minute.
Finish 3 games of Mah-jong without reshuffling.
Complete the Bonus Chapter (Any Difficulty).