Cloud City 4-3 is the third level of Cloud City. To pass this level with three stars, you should pop all pigs and score at least 74,000 points.
This level needs a bit of luck to destroy the towers.
Send Leia into the bottom-left steam vent, allowing her to loop across the entire level. Pull the right side of the main structure with her tractor beam, and Leia can continue onward into the two remaining floating platforms. Cause entire level will be destroyed.