I don't mean to be negative, but I can see it now. The home team is down by 5 points, and throws a sure-thing TD pass to an open receiver in that end zone with time expiring during the down, and one of those kids - paying no attention to the real game - decides to kick their ball and it flies into the end zone and 1) deflects the pass, 2) the receiver steps on the ball breaking his ankle and missing the catch, 3) the receiver thinks the kid's ball is the real game ball and catches it, while the real ball flies past, incomplete. What a mess.
As an Architect, I have planned play areas for children at football stadia. They are far more removed from the real playing field, and are usually enclosed with a fence, but are within easy sight of the grandstands, so their parents can keep an eye on them. This is a noble idea, but not well thought out.