At Duarte we have this club called Film Bites. We watch short films once a month and sometimes we create our own. We had one that was an exercise where several designer collaborated together to create one final piece. The ask was that each of us create a 5 second clip that could be of anything you wanted. The only requirement was that the animation starts and ends in a circle and that you used the given color palette.
Below is my contribution.
I went with a space theme. It seemed to me that there were lots of options for round shapes with this subject. I built my assets in illustrator, my animation in keynote, and added sound effects through iMovie.