How to make a particle system do light rays

I am trying to get an effect similar to the gems in this ball game demo - Ball Game made with Unity3. V2 - YouTube.

The developer says it is particles with ’ just some low random speed + high speed stretching’ but for the life of me I can’t seem to duplicate the effect.

Can anyone shed some light on this technique/effect and how to achieve it.

Thanks

There is a generator on the asset store Unity Asset Store - The Best Assets for Game Making

It can generate a similar effect in all directions, altough the shafts can not be animated seperatly, it is possible to animate the whole generator, or child it under an already animated object.