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