Here is an english spoiler free Achievement guide version.
Story related Achievements
ABYSS OF THE SACRIFICE
Good luck and godspeed.
The sky’s the limit.
Tomorrow is another day.
You’ve got a chance.
Hope all goes well with you.
I’ve got a bad feeling about this…
God bless you.
Survive!
Keep your faith.
Hopeless
True Surface
Badland
Faded
Final Trial
Endless
Fly Again
Last Dream?
All character routes
After that, you can always start with Bad Omen
Bad Omen → Fake → Wings → Revelation → Sacrifice → Feather
Bad Omen → Fake → Six → Feelings → Loop
Bad Omen → Lockout → Wings → Revelation → Sacrifice → Operation → Seal
Go back to Contagion and then Bad Omen → Wings → Sacrifice → Revelation → Eternity
Contagion → Host ⇄ Guardian Angel → Awakening → Bad Omen → Wings → Six → Lockout → Fake → Accident → Zero → Surface
Additional Achievements
The tea brewed came out mediocre. Olga’s father would never be satisfied with this.
Obtainable in chapter “Tea”.
Follor the instruction given as per normal but use the normal black tea can instead of the special tea.
Played Orange to a draw in Unit Battle. What Chloe desires, however, is a perfect victory.
Obtainable in chapter “Path”.
From left to right of the units:
4-6- Attack-1-5-3-3-2
Entered “JITKA” into the cold sleep pod.
Obtainable in chapter “Zero”.
You’re required to see all other endings before you get the opportunity to enter the password into the cold sleep pot.
Held the maximum number of items. Even with Miki and Chloe working together, 12 items is the max.
Obtainable in chapter “Feather”.
You have to “combine” 3 pieces to gather a random (& incorrect) hologram form.
1. Red, Blue cross & Yellow
2. Red, Blue cross & White
3. Cyan star, grey triangles & Blue cross
4. Combine Red & Yellow in your inventory. Then attach it below to obtain Orange.
Mix Orange, white & green. ⟶ After obtaining the fragment, put orange back & detach the combined 2 colors.