After completing the moon, do the stage again and make the moon into stardust. This gives you a movie of the little boy saying how rich people are different.
The Moon Memorial is unlocked once you complete the Make the Moon level. It allows you to view cutscenes and listen to the game's soundtrack.
Eternal 1 Build up the ball past 1m30cm before the time runs out in Make a Star 4.
Eternal 2 Build up the ball past 25m before the time runs out in Make a Star 8.
Eternal 3 Build up the ball past 800m before the time runs out in Make the Moon.