Click the green flag and watch.
As far as I know, @Scratch-Minion was the first to realize a pen kaleidoscope project on Scratch (https://scratch.mit.edu/projects/183185603/). Many Scratchers have been inspired by it. The best projects are collected in this studio: https://scratch.mit.edu/studios/4447486/ What makes this project special here is the fact that it was created with the simplest possible means (no clones, no custom blocks). This increases the chance that its code will also be understood by less experienced Scratchers.
