Kill all pigs in first second shot is hard. Getting 3 stars in this level is very hard.
One stratgy for Utopia 4-2 is aim the Black bird between the left-point and the asteriod just below it. Detonate the bird in the the bird in the middle of the pile and hope to pop as piggies in the pockets as possible.The way to earn three stars is to use as few birds as possible.
This level resembles pool game (or bowling, for that matter).