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.
Find all the meditation statues.
Add all secret shells to your collection.
Complete the adventure.
Discover the polar region.
Breach the water on the back of a blue whale.
Ride the Great White Shark.
Discover those that lurk in the abyss.
Burst 15 fish schools in the jetstream.
Witness predation while meditating.
Perform a flip while riding a creature.
Leap from the water.