When watching two dogs interact, we're often asked, "Is that okay?" Dogs can play rough. They grab each other, growl, roll around on the ground... So what is good dog play?
Good play is mutual. Both dogs are engaged and interested in interacting.
Good play is about loose, relaxed, floppy bodies. Play movements should be inefficient and floppy, like a puppy.
Good play is about taking turns. If one dog is on top, that dog should back off after a few seconds and not simply pin the other dog under their body.