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 36!
Finish level 37!
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!
Activate blue plant 25 times!
Activate green plant 25 times!
Activate green plant 20 times!
Activate blue plant 20 times!
Activate green plant 15 times!
Activate red plant 25 times!
Activate blue plant 15 times!
Activate green plant 10 times!
Activate red plant 20 times!
Activate green plant 5 times!
Finish level 23!
Activate yellow plant 25 times!
Finish level 22!
Finish level 21!
Finish level 20!
Activate blue plant 10 times!
Finish level 19!
Activate yellow plant 20 times!
Finish level 18!
Activate red plant 15 times!
Finish level 17!
Finish level 16!
Activate blue plant 5 times!
Activate yellow plant 15 times!
Finish level 15!
Finish level 14!
Finish level 13!
Finish level 12!
Activate red plant 10 times!
Activate yellow plant 10 times!
Die 25 time!
Finish level 11!
Finish level 10!
Finish level 9!
Activate yellow plant 5 times!
Die 15 time!
Activate red plant 5 times!
Finish level 8!
Use flip 100 times!
Use flip 90 times!
Finish level 7!
Use flip 80 times!
Die 10 time!
Finish level 6!
Use flip 70 times!
Use flip 60 times!
Use flip 50 times!
Finish level 5!
Use flip 40 times!
Die 5 time!
Finish level 4!
Finish level 3!
Use flip 30 times!
Finish level 2!
Use flip 20 times!
Use flip 10 times!
Finish level 1!
Use flip 5 times!
Die 1 time!
Use flip for the first time!
Play the game!