Thanks for playing! Oh, I should've explained it better. The sparks are a mechanic known in some bullet hells as "graze", which is getting super close to the bullets without touching them. In Faecula, getting graze fills your magic bar and allows you to consume it to slowdown time. You enable the "graze" ability by picking up the magic ball. So it's like a risk/reward thing, you can try to play more dangerously in easier patterns in order to have magic to slowdown time in the harder portions of the stage.