I saw this video the other day of a man and child playing "analog Tetris" and I wondered where the board came from. A search revealed other versions but not this particular one. It was only today that I realized that it's cardboard and probably homemade. THEN I came across THIS video that explains it ALL.
A father from central China's Henan province makes toys for his five-year-old daughter using low-cost materials, such as cardboard. He hopes parents can spend more time with their children and encourage them to use screens less.