What began as an apparent cash-in on the rising popularity of “The Walking Dead” franchise thanks to the then-newly celebrated TV series and long-running comic book turned into an emotional juggernaut for gamers who enjoyed making tough decisions, listening to bitter conversations, and wanted to parent that greatest kid ever wearing a dingy baseball cap. Now Clementine returns, but she’s not alone as I begin my playthrough of “The Walking Dead: A New Frontier” Playthrough.