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