As far as describing the "Nano Spores", It seems that each spore just traces out a straightline between its original spot and another random spot on the circle. That random spot stays constant for each mouse click. The spheres themselves have a sort of velocity function that seems to have a constant curve (a hump of sorts: v=-ax(1-x) or something (for 0<x<1) ), but is sped up or slowed down relative to the other sphere's randomly with another random parameter that also stays fixed for each click. So as far as "clever" geometry, its really not too complicated and could be made a lot more complex if the parameters weren't fixed for each mouseclick. How difficult that would be I wouldn't know as I haven't actually looked too closely at the source code.

It is cool to look at though! All the different speeds and transparencies really does look sweet.