You could make the first part of the experience free-fall (throw people with a magnet strapped on down a tube that is conductive only near the bottom).

I think the big problems are that you need a hefty magnet (which is inherently dangerous) and you can't really split up the magnets over the body (because that is INSANELY dangerous), so you experience that same thing that could be achieved via bungee cord/harness.

You would also need to limit (lateral) movement quite a bit, to get reliable braking...

A x-shaped magnet assembly strapped to the back could work, but you probably could not allow the tube being all that much bigger in diameter than that backpack...

edit: If you allow any fall configuration different from feet-first, the terminal velocity has to be pretty low to reliably not kill people, too. But you could make this work with a net, I think...