I loved the ramps and movement of this video as a kid... and the mysterious and abrupt holes that apparently send the ball to one of many levels of this strange

I loved the ramps and movement of this video as a kid... and the mysterious and abrupt holes that apparently send the ball to one of many levels of this strange contraption/world. I got the same feelings with Commander Mark and The Secret City, the PBS drawing show: https://en.m.wikipedia.org/wiki/The_Secret_City https://en.m.wikipedia.org/wiki/The_Secret_City (also on YouTube, though the video quality is disappointing)