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