I owned a unicycle, and then gave it to a friend who rode it around town and after school. He got pretty good at it, but I couldn’t do it myself. That’s mainly why I gave it away to him.
As for the bike you shared, I never rode one of those, but I think it’d be fun to try.
I rode by friends tandem bicycle, it was fun. Little hard to control and balance at first, after that was fun riding. It’s specially good if you drive it in scenic roads.
These are very strange ones. I used to love to watch these on television when I was in kid. I don’t know how could one balance in like these type bikes.