Here is the full list of all 35 STEINS;GATE: Linear Bounded Phenogram achievements.
Unlocked a 1st stage scenario.
Opened the MOVIE LIBRARY.
Opened the SOUND LIBRARY.
Opened the CG LIBRARY.
Opened the CLEAR LIST.
Cleared "Dr. Jekyll Online."
Cleared the game with an unread message in Phone Trigger.
Opened the TIPS LIST.
Changed the ringtone for Phone Trigger.
Changed the wallpaper on the Phone Trigger standby screen.
Viewed Phone Trigger transmission history at least once.
Replied to a message from someone in Phone Trigger.
Viewed a message in the Phone Trigger reception history at least once.
Started STEINS;GATE - Linear Bounded Phenogram.
Completed everything in STEINS;GATE - Linear Bounded Phenogram.
Cleared "The Caged Bird Sings."
Cleared "Vermillion Soteria."
Cleared "Ghostly Rendezvous."
Cleared "Built with Love."
Cleared "Superhero Chat-Noir."
Cleared "Hermaphroditus in the Labyrinth."
Cleared "Eternal Polaris."
Cleared "The Quantum Awakening."
Cleared "Abduction Across Three Worlds."
Cleared "Lunar Bifröst."
Unlocked 25% of CGs.
Unlocked 50% of CGs.
Unlocked 75% of CGs.
Unlocked all CGs.
Viewed all TIPS.
Viewed all messages.
Unlocked a 2nd stage scenario.
Unlocked a 3rd stage scenario.
Unlocked a final scenario.
Unlocked a hidden scenario.