Here is the full list of all 20 Gravitas achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Find the last Shark.
Your mom would be proud.
Solve Level 4's puzzle correctly.
Find the fourth Shark.
Find the third Shark.
Find the Shark in...what are you even doing here?
Find a Shark in its natural habitat.
Test the Curator's groundbreaking new technology in Level 3.
Use only one box to beat The Garden of Gravity.
Jump the gap before getting the glove.
Finish the game.
It's never a bad time for SCIENCE. Except this time, this time was pretty bad.
Complete Level 5.
Complete Level 4.
Complete Level 3.
Complete Level 2.
Complete The Garden of Gravity.
Complete Level 1.
Meet the Curator and complete his training.
Show your eagerness to learn, early on.