Hiking is quite popular with travelers and locals in the Adelaide region. If you're after more outdoor adventures, go four-wheel driving as well.
Playford is great, but don't spend your whole trip there! Get out and explore the surrounding area. Elizabeth is a top-notch place to start. Located just .3 miles away, it's the perfect way to spend some time.
Be sure to pack a good book and maybe even a volleyball. Playford has some awesome beaches you can cruise to, such as: