I started a blog on my website and released the brush set I created and use for a lot of my work in Procreate. The post shows examples and explains a bit about how I use a few of the brush. At the bottom of the post is a link to the itch.io page where you can acquire it if you would like to try them.
I think they wanted you to play multiple loops of the game to get a higher score instead of sitting on bosses that didn't have a self-destruct counter implemented.