No idea what you're talking about. Pics please?You seems to get things looking like packs of missiles or the like floating around which you can shoot and blow up?
Some of the tunnels have destructible structures in them. Shooting them makes tunnel combat more interesting.
They do no splash damage. It's completely aesthetic. But there isn't really enough of it to make a difference (adding to the intensity of the matches). I hardly see it get hit because there isn't a lot of interactive debris