Here is the full list of all 10 Sky Ball achievements.
Drop 100 vases
Collect all the cores
Complete one level 2 times
Complete all levels
Finish Level 4 in 1 minute 30 second
Do not do anything for 15 minutes
Complete all levels in one pass
Die 100 times
Complete all levels at once without falling
Complete all levels at once without falling and while collecting all the cores