I would think that you would to give it a solid foundation they'll be able to dribble and jump on

A concrete or asphalt base is ideal however you can do a compacted aggregate and membrane or a portable type temporary sub surface. Again our recommendation for longevity and best rebound of your game ball is always concrete or asphalt installed per specs. Www.fullcourtathletics.com

Thank you.

I was hoping for something simple but it looks like I have to extend my creativity.

love that you're doing this! will try to do the same for my boy when he's a little older. would have loved one of these growing up!