There was a time when playgrounds were simply a place that kids were dropped off and told to be home before dinner. These days, if you’re just hanging around watching your kids play (as opposed to actively engaging them in an effort to out-parent the next guy) then you and the kid are probably both falling behind. This carefully curated selection of stuff for you and them will keep you both energized and fully charged for a few hours of unstructured — but really productive! — play. As for the guy just dropping his kids off and telling them to be home before dinner? You’re probably supposed to call the cops.