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