Too bad, I am greatly disappointed.

Can only agree with my predecessor. For one evening, everything went well. Also has a lot of fun. The next evening the air was out. While reaching to the air pump, I realized that the air exhaled audibly, to the holding in the center of the ball. Had the very hard ball even done something supple when assembling under warm water, so it can not have been. And, the included air pump is anything but reassuring.