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