Get the indicated amount of points by collecting "I" symbols in Free Flight mode to unlock the corresponding bonus.

Balloons appear over Wuhu Island: 10 points.
Evening mode: 20 points.
Double Popper: 30 points.
New Whale Shark design featuring your Mii: 70 points.
Night fireworks lighting: 50 points.
Night mode: 40 points.
Two-seater plane: 60 points.
Vacation house: 80 points.