Walk into Helena Walter Higgins’s home in Thornton and it’s like walking into an arcade. There are about a dozen full-size pinball machines lining the walls of the living room, and just as many in the basement, paneling the perimeter of the room. When the machines are all turned on at the same time, they blink and scintillate and honk and jingle from all directions in a chorus of nostalgia. On a recent day, Walter Higgins leaned over one of her favorite games upstairs, “Dracula,” and swept her long black hair behind her shoulders before taking her position over the game, eyes fixed on the glittering obstacle course between her hands. “I’ve been playing pinball almost every day for 27 years, but I’ve only competed since 2002,” Walter Higgins, 41, said.