Here is the full list of all 15 Gemini Rue achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Complete the game once in Commentary mode
Complete all fights without losing any health
Complete the game once
Access the Memory Database in the Director’s Office in Center 7
Escape Center 7 without losing any health
Find all 4 hidden Easter Egg Characters
Find all Database Articles
Analyze a photo using the terminal
Find all 3 extra ammo magazines
Heal the fellow Man on Barracus
Find all 6 hidden notes in Center 7
Complete all Center 7 Exams without any strikes
Be able to control both Azriel & Delta-Six
Evade the Boryokudan rather than fight them
Take the stairs instead of the elevator