Here is the full list of all 46 BURIED STARS achievements.
Played the game for the first time.
Began the first keyword conversation.
Acquired a new keyword with the conversation.
Finished my first recapitulation.
Changed the Auto-Write message.
Opened the watch menu.
Changed the watch settings.
Listened to a recording file.
You've gone crazy.
Recovered more than half of Mental Gage.
Saw all of Juyoung's rapport events.
Saw all of Hyesung's rapport events.
Saw all of Inha's rapport events.
Saw all of Gyu-hyuk's rapport events.
Saw all of Seil's rapport events.
Saw a particular epilogue event after getting rescued.
Saw the true ending.
Rescued after failing to discover the truth.
Rescued but gave up on truth.
Rescued but couldn't complete the picture.
Couldn't take another step before the truth.
Encountered the conclusion of another possibility.
Saw the first ending.
Encountered the attacker at the site.
Encountered the attacker unexpectedly.
Fell into eternal purgatory.
Discovered the existence of the hidden command center.