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