I can help you, but only a bit.
You need a Particles Object (I don’t know if this feature is available for web platform games).
Then, when you click on the object A, you should create the Particles Object over the object A, wait some time and delete the Particles.
The problem is that you have to set the particles properly, It has a lot of options and take a lot of parameters (time between particles, life time 1, life time 2, initial color, final color, angle, force, dispersion, etc., etc., etc.) 