A surprisingly wide range of animals will engage in play behavior
Bumblebees have been shown to love having small beads around for them to roll around and on
Edit: sheer amount of people replying who can't just let the silly birb have fun. Guess what, dogs and cats derive play behaviors from predation too, doesn't mean that play ain't play.
I think you're right, but i also remember learnning that some birds have learned to break nuts open using concrete, which i think is what this bird is trying to do