Here is the full list of all 9 The Upside Down achievements.
Running low on Oxygen!
I have to say, this weapon is powerful!
Thank God fuel regenerates!
First one but sure not the last one!
First step for me, but biggest step for the "Black Sky"
Portal to the Upside Down!
Top Secret Laboratory located in Wankings, Indiana
Raising Suspicion
Welcome to the game!