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