Here is the full list of all 78 Upside Down achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Finish level 40!
Finish level 39!
Finish level 38!
Finish level 37!
Finish level 36!
Finish level 35!
Finish level 34!
Finish level 33!
Finish level 32!
Finish level 31!
Finish level 30!
Finish level 29!
Finish level 28!
Finish level 27!
Finish level 26!
Finish level 25!
Finish level 24!
Finish level 23!
Activate green plant 25 times!
Activate green plant 20 times!
Activate green plant 15 times!
Activate green plant 10 times!
Activate green plant 5 times!
Finish level 22!
Finish level 21!
Finish level 20!
Finish level 19!
Finish level 18!
Finish level 17!
Finish level 16!
Finish level 15!
Finish level 14!
Finish level 13!
Finish level 12!
Finish level 11!
Finish level 10!
Finish level 9!
Activate blue plant 25 times!
Activate blue plant 20 times!
Activate blue plant 15 times!
Activate blue plant 10 times!
Activate blue plant 5 times!
Activate yellow plant 25 times!
Activate yellow plant 20 times!
Activate yellow plant 15 times!
Activate yellow plant 10 times!
Activate yellow plant 5 times!
Activate red plant 25 times!
Activate red plant 20 times!
Activate red plant 15 times!
Activate red plant 10 times!
Activate red plant 5 times!
Finish level 8!
Finish level 7!
Finish level 6!
Finish level 5!
Finish level 4!
Finish level 3!
Finish level 2!
Finish level 1!
Die 25 time!
Die 15 time!
Die 10 time!
Die 5 time!
Die 1 time!
Use flip 100 times!
Use flip 90 times!
Use flip 80 times!
Use flip 70 times!
Use flip 60 times!
Use flip 50 times!
Use flip 40 times!
Use flip 30 times!
Use flip 20 times!
Use flip 10 times!
Use flip 5 times!
Use flip for the first time!
Play the game!