Here is the full list of all 13 Marble Skies achievements.
Roll your marble 100 Kilometers.
Bounce your marble really high!
Fall off the map 1000 times.
Fall off the map 100 times.
Complete every state in Beginner, Intermediate, and Advance
Complete all Advanced stages
Get a World Record time on any level.
Play your first Advanced Level
Complete all Advance stages
Play your first Intermediate Level
Complete all Beginner stages
Fall off any level for the first time.
Play your first Beginner Level