a zip line with some bicycle handlebars
Our daughter and S_I_L have a couple of acres with some nice trees, I scrounged up a couple of hundred feet of 3/8 cable...
And I like your handlebar idea!
Have a nice flat bar from a mountain bike in stock...
For the grandkids.
I just bolted a little pulley on the center of the bars and strapped the cable between two trees... The biggest problem we ran into was that some dogs had pooped in the landing zone which we didn't notice until afterward. My grandparent's neighbors had a similar setup in their field when I was growing up. Their field sloped down so they didn't need an extension ladder at the launch spot to get good speed.