Here is the full list of all 29 DE-EXIT - there are Eternal Matters achievements worth 1,000 gamerscore.
Complete the Prologue
Complete Chapter 1
Complete Chapter 2
Complete Chapter 3
Complete Chapter 4
Complete Chapter 5
Sneak away from the enemies in the Prologue without being caught.
Solve the priest puzzle.
Don't die during the chase of Chapter 2.
Don't die during the boss fight of Chapter 3.
Complete the puzzle within a limited time frame.
Activate all panels in the temple entrance of Chapter 5 without touching the snowy ground.
Find a soul fragment.
Find all soul fragments.
Equip a piece of the Guardian armor.
Equip the full Guardian armor.
Read a lore point.
Read all books in the library.