i will look at this lather more intensive, but at the moment ive no time for this...

but your problem is, that you dont see any effect now, right?

look at your code - you are creating one particle of a size of 3 and a lifespan of 5 ... ich would say, first for testing increase the size and number.
tham check if the are to slow in movement (1 to -1 is slow) and play with the lifespan/fade off.

this could solve your problem^^