Here is the full list of all 17 Fallen Seeds achievements.
Meet Lily
You stood up for Lily
You sided with Doug and Martin
Meet Enigmatic Fox Girl
Meet Kaya
Ending: you remained loyal to the Empire and abandoned the search
Ending: you found the answer to the ultimate question of life, the Universe, and everything
Meet Ophelia
Meet Sif
You've completed a route
Ending: you are keeping your goal and loyalty to the humanity
Ending: you assist Ophelia
Ending: new adventure with Lily awaits
Ending: you teamed up with Ada
Ending: you dive into the mysteries of science with Sif
Ending: you formed a deadly alliance with Kaya
Ending: you survived this party, get ready for the next one!