Here is the full list of all 12 Always The Same Blue Sky... achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Alienate yourself from Kira as much as possible
Endear yourself to Kira as much as possible
Captivated by what could be...
Demonstrate a firm scientific grasp
Travel to an undiscovered land
Try 2 different milkshakes
Reach ending 2
A calming glow
Reach ending 1
Visit the ancient courtyard
Take note of your surroundings
A burning fire