Here is the full list of all 20 Carto achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Finish the three levels of the Tower of Hanoi in the fewest steps.
Complete the game 100%.
Visit the airship.
Finish snowman buddy.
Find something mysterious in the lake.
Behold the legendary flame tornado!
Listen to the quartet of birds.
Learn nothing about cactuses.
Give a plant your full support.
Finish chapter 10.
Read all stories in the Story Chalet.
Finish chapter 9.
Finish chapter 8.
Finish chapter 7.
Finish chapter 6.
Finish chapter 5.
Finish chapter 4.
Finish chapter 3.
Finish chapter 2.
Finish chapter 1.