Our bunnies play run and chase games too... I tend to think it's somewhat competitive, or sexual, or both. :~) Last night there were two who were out hop-hop-hopping around, and they suddenly charged at each other, and when they met, both LEAPED 2-3 feet straight up in the air! -Then they landed and ran away... ~shrugs~ I don't know what that was, they surprised each other :~)
Interesting! I guess I've just never thought of rabbits as being aggressive/physical with each other. To me, bunnies were always just cute little fuzzies that kinda just mosey around the yard, but I've never been around very many to speak of either.
I saw something else I'd never seen before the other afternoon when I was driving to the barn. At first I thought it was 3 small brown dogs running down the side of the road, but on closer inspection, it was 3 rabbits running in single file down the side of the road, in broad daylight. They dashed into the underbrush as I passed, but it was really strange! Who knows what they were up to.