Click the green flag to start the animation. Use the sliders to change its appearance. I have commented the code inside, so take a look :)
I really liked the original project, so I thought I'd make a remix to show how it could be done with clones instead of separate sprites. The code is a bit more complicated, but once you get the hang of it, this method is much quicker. Also, it is very easy to adjust all of the clones by changing a single value.