Here is the full list of all 5 Narcissu 1st & 2nd achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Finished Narcissu 2nd Epilogue
Finished Narcissu 2nd (unvoiced)
Finished Narcissu 2nd (voiced)
Finished Narcissu 1st (unvoiced)
Finished Narcissu 1st (voiced)