In Japan, parks tend to be fairly barren (Martians could land and wondered how they got home so quickly). Still, we can draw in the sand.
This morning was too windy to play bat & ball, so I scratched a start point and a a circle for the target, then filled the space between with obstacles such as a hungry bear or a raging river (adjectives get a look in too…).
The goal is to use the bat to get the ball into the circle without going over the obstacles. If you roll over the bear, you ‘were eaten’ by the hungry bear (etc etc).
Simple fun, fairly effective!