You can get all three stars in this level by only using three angry birds.
- Aim the first angry bird at the top left corner of the structure on the right. You need to take out all five birds on the right side.
- Aim the second angry bird and drop it’s egg bomb right in the middle of the main structure to clear out a bit of the rock.
- Aim the third angry bird at a high angle to break through the middle of the main structure that you jsut cleared out. Do NOT let the bird get all the way to the ground before exploding. I found it best to detonate it early right as it goes through the ceiling rocks in order to get the last pigs.