Getting excited over interactive animations like is just one of those things I’ve never really outgrown!
If you circles with the mouse around the particles, faster than the speed of particles, they get caught in the “mouse event horizon” and cannot escape.
Not a black hole, but a colourful finger…
Edit: hmmm, this could actually be a new game idea. If particles touches mouse they explodes, if mouse circles around particles, they form blob, etc