Yeah, we do something like that, too. :) But, in order to do this safely, the horse has to respect his handler, be very aware of personal space and accept him as a lead horse. If the handler is not a real leader for the horse and has poor body language, such games can quickly turn dangerous - for example, a horse can rear as he would when playing with another horse, and, if the handler will shy away, the horse can learn that rearing is a way to dominate, or even charge or kick out within the borders of the handlers' personal space.
And, to get to a spot where playing is fun for both horse and the handler, groundwork and lots of undemanding time together are crucial. :)
Hah, I tricked the Universe today and managed to visit Snickers after all, and I even got a ride home in the car of a horsey friend who suddenly decided to visit us. :)
I have come a long way, to surrender my shadow to the shadow of my horse.