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.
Captivated by what could be...
Alienate yourself from Kira as much as possible
Endear yourself to Kira as much as possible
Reach ending 2
Demonstrate a firm scientific grasp
Take note of your surroundings
A calming glow
Travel to an undiscovered land
Reach ending 1
Visit the ancient courtyard
Try 2 different milkshakes
A burning fire