Full list of all 20 Caterpillar (Windows) achievements worth 3,000 gamerscore. It takes around 0-0.5 hours to unlock all of the achievements in the base game.
The base game contains 10 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 10 achievements worth 2,000 Gamerscore.
Level 10 started
Level 9 started
Level 8 started
Level 7 started
Level 6 started
Level 5 started
Level 4 started
Level 3 started
Level 2 started
Level 1 started
You must eat all the flowers in level 1
You must eat all the flowers in level 2
You must start the level 11
You must start the level 12
You must start the level 13
Start the Level 14
Start the Level 15
Start the Level 16
Start the Level 17
Start the Level 18