Here is the full list of all 25 Through The Fragmentation achievements.
Find the strange entity living on the edge of the Fragmentation
Meet the insane one living in the Fragmentation
Find a way to enter the mysterious Fragmentation
Turn off the game from the mysterious level
Find the correct password and login to the office computer
Steal and eat the sandwhich of the janitor
Have a chat with the office worker during his smoking break
Find and talk to the Hermit who lives in the office building
Listen to the thoughts of the melancholic bird
Create another way to the apartment building
Enter the city sewers
Leave the City
Find all 17 pendulum birds in one playthrough
Take a shower while exploring the apartment
Help out the one who got stuck in the restroom
Spend some time on the passenger seat
Visit the eccentric once again after returning from downtown
Collect more than 1k points in the Labyrinth minigame
Jump or fall into the dark abyss
Sell the data disc to the stranger
Get locked out of the office computer
Collect more than 10k points in the Labyrinth minigame
Find the lost one in the Fragmentation
Complete the game
Get access to the hidden place in the city sewers