To get the three star mastery, you will have to kill all the pigs with just one shot. Aim to pass the first house and fly under the black pig.
Power Activation Point
Activate the special power when you are under the black pig. Remember to tap where the pig is.
First Shot Result
The black pig gets pushed and the metal square falls down to kill the pig on the left. You break the chains with wooden blocks, the chains fall down and trigger the TNT box and annihilate the rest of the pigs. Your Anakin bird may also trigger the bomb if you are lucky. This stage may require multiple tries for you to succeed.