Here is the full list of all 14 Submerged: Hidden Depths achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Collect all Creatures
Collect all Styles
Finish the Campaign
Collect all Flowers
Collect all Diaries
Change Body Style
Change Hair Style
Change Boat Style
Put a Flower in your hair
View a Relic at the Home Base
Use all Lookouts
Collect all Relics
Collect all Boat Boosts
Visit all Landmarks