Here is the full list of all 16 WATCH achievements.
Rotate camera view for the first time
Activate
Encounter the Sprite for the first time
Get all sprites
Get the Video for the first time
Pass the first chapter
Pass the first chapter with No Death
Rigel is lit
Saiph is lit
Bellatrix is lit
Belt is lit
Betelgeuse is lit
Orion is lit
Pass the second chapter
Pass the second chapter with No Death
Eye is lit