It is organic improv. A suggestion leads to a group group game. The "form" is a constant morphing of one organic game into the next, attempting to recognize patterns and call-back games. There was the occasional scene, but the key was that all of the performers (usually 5-7) were on-stage and involved the entire time, so a 2 person scene always featured the rest of the group portraying environment.
It usually lasted 25-35 minutes, and would end with a performer stepping forward to get the suggestion again--the idea being that the show took place entirely inside the brain in the split second when the suggestion is yelled out.
- Discussed on the IRC Improvisation forum.