Here is the full list of all 13 Doorways: Prelude achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Collect all Relics
Collect all Relics of Marble from The Cave
Pickup all notes
Finish Chapter 2
Collect all relics of Bronze from The Auditorium
Pickup all notes from The Auditorium
Find all Museum paints
Finish Chapter 1
Find all Torture sketches
Pickup all notes from The Forest of Stakes
Collect all Relics of Metal from The Forest of Stakes
Collect your first Relic
Finish the Tutorial