Here is the full list of all 12 ABZU achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Release fish from all the hidden pools.
Discover the polar region.
Add all secret shells to your collection.
Find all the meditation statues.
Ride the Great White Shark.
Complete the adventure.
Breach the water on the back of a blue whale.
Perform a flip while riding a creature.
Discover those that lurk in the abyss.
Witness predation while meditating.
Burst 15 fish schools in the jetstream.
Leap from the water.