Here is the full list of all 17 Forestation achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Pass all forest levels
Pass level 30 successfully
Pass all levels by 100%
Find all secret trees
Pass all swamp levels
Find 25 secrets trees
Pass all desert levels
Find 10 secret trees
Make the duck quack
Find the first secret tree
Pass 10 levels
Stop 25 times
Visit the game between December 31 and January 3.
Stop 10 times
Unlock all 10 islands
Pass the first level