There were these large bicycle-sized animals that you could jump on and ride around the mall. Essentially, like a battery-powered, indoor 4x4 for kids.
They were free to go wherever they wished, as long as it didn't run into anything, and didn't go in any stores.
So for twenty bucks, they ended up zipping around the mall for about 15 minutes, having the time of their life. A good business idea, and some good, clean fun!