My boys have very little. My oldest is pretty rough so it ends in tears as the youngest isn't thrilled with it. I try to leave them to it but the youngest ends up coming and looking for salvation.

At times they've been able to play for 30 mins or so without incident outside.

Also, my oldest gets pretty anxious so doesn't really like to be without an adult. Says he gets scared so never plays in his room or out the back alone.

It's something that is an ongoing project.