Here is the full list of all 9 Switchball HD achievements.
Complete Sky World level 3 - 10 points
Complete Ice World - 15 points
Complete Cave World - 15 points
Complete Lava World - 25 points
Collect one Silver Medal - 5 points
Collect 12 Silver Medals - 10 points
Collect 24 Silver Medals - 20 points
Collect gold Medal on all levels - 30 points
Find Three hidden paths - 15 points