i think the whole point is to distract you with the particles!
even if they are absolutely not nessessary- moving anywhere while you are in a small area constantly avoiding to be hit and because you only have 4 hp while each wave gets bigger and more out of control you need to have a fast working brain and hands while bullets and/or enemies moving towards ya - i think the hole idea is ment to make this deam difficult- not to entertain and "let us just play” like to reach perfect score 1. try!
But yes, I understand your concern very well, My brain is burning at the moment : D.