Had the idea after seeing some demos which looked it but didn't really do it.
These galaxy collision type graphics required a superconfuser during the C64's days, computing F=MA millions of times, recursively. The hope would be to somehow simplify it to achieve a lower res particle effect on a commodore. It would use fewer particles, 2D only, entirely lookup tables, 320x200 bitmap mode, possibly only 0-256 X.
The number of calculations possible for a single particle are bugger all on a 6502. The hope would be to hard code some kind of motion vector table for each particle to achieve a swirling effect. Maybe there could be an XY to polar conversion. For short animations, the solution is normally a color palette change rather than a redrawing of every pixel. To prove it's not a color palette animation, it would have to be long.