It's not a martial art, to me, but it's fun to think of it that way!
I haven't played in twenty years. Last time, there were forty of us. All karate guys and cops. We played indoors, in an huge abandoned shoe factory that a paintball company took over. There were four young men who were our hosts/referees. They were nice guys, played organized paintball across the country, and had their own customized paintball guns.
About an hour in, some of the guys with us (from different martial arts schools) got a little hot under the collar and lost their gentlemanly ways. It started to get ugly. The referees warned us once. When it happened a second time, a real fistfight was about to start when the refs took us to the woodshed. They just opened up on us. Their guns were faster, more accurate, and hit much harder. The suckers REALLY HURT. They also knew what they were doing. They chased us and just slaughtered us. Oh, what an *** whooping we got for about two minutes. Even though it was only a handful of guys who had gotten out of line, the refs figured we ALL deserved a lesson for not controlling each other. And they were right.
They finally stopped and asked, "You men want to behave, or would you like some more?" We waved white flags and apologized profusely, a couple of the guys even politely laughed and bowed. And we sure as heck behaved from then on out.
I've played a few times. I liked indoors more than outdoors, there was more, I don't know, tension maybe, going from room to room waiting to get bushwhacked. I see similarities to martial arts, but maybe because they're both a lot of fun.