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