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