Here is the full list of all 11 Enigmatis: The Ghosts of Maple Creek achievements worth 1,000 gamerscore.
Finish any Mini-Game in less than 1 minute.
Finish 7 Hidden Object Puzzles in a row without using hints.
Finish all Hidden Object Puzzles without using hints.
Finish any Hidden Object Puzzle with less than 4 mistakes.
Find 3 hidden-objects within 3 seconds.
Finish any Hidden Object Puzzle in less than 1 minute.
Finish 6 Mini-Games in a row without skipping.
Finish all Mini-Games without skipping.
Finish game on normal difficulty
Finish game on expert difficulty
Finish the bonus chapter.