Derby <3
There is nothing you cant do, damage to others is hard to detect, but you can do it like this: Everytime sb. gets damage or explodes, everybody else is getting some "survivor points".
There could also be special pickups like canons or Tornado attack, explosives etc etc.
I once started to script something like that, but unfortunately I had no time to finish it.
Would be great to have something like that on Adrenaline