Here is the full list of all 12 Shuffle! achievements.
Completed the Primula route.
Completed the gallery.
Completed the Lisianthus route.
Completed Lisianthus's True Ending
Completed the Kareha route
Completed the Mayumi Thyme route.
Completed the Nerine route.
Completed the Asa Shigure route.
Completed the Kaede Fuyo route
Watched the first opening movie.
Started the game.
Opened the gallery.