After Steven Spielberg changed the movie world with Jaws in 1975, he bought a cavernous Beverley Hills home and filled it with arcade machines. Newly minted and paranoid, the director also installed an elaborate security system, and refused to accept deliveries at the door. Hollywood’s hottest director and his walled-off playpen. Ready Player One is a film built for Spielberg The Younger, from Spielberg The Elder, a cautionary celebration of pop culture toy islands, a messy, whizzing trip into the lens-flare fantasies of the geek id. In Ready Player One, ‘the OASIS’ is the biggest toy-box ever invented. A giant virtual reality and intensely lucrative…