“Game of Thrones” play “The Mad King” finally launched previews Tuesday night after cancelling its first week of performances. The first ever run-through of the HBO/Royal Shakespeare Company co-production, which takes place before the events in HBO’s “Game of Thrones” series, earned a standing ovation from the enraptured audience. Popular on VarietyHowever, the performance ran without a hitch and there were no unscheduled show stops during the four-hour performance. A rep for the RSC said the team had already received “incredible” feedback online and via email. In response the RSC has added a handful of extra performances but few tickets are available for the remainder of the show’s two-month run.