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