Antigravity Marble Game

Based on the "Shoot The Moon" game, this is a pocket-sized version that is fairly easy to play, and you can use various size marbles or steel balls (15 and 20 mm work well). STL file included so you can scale it to larger size if desired. Note that the control rails are rectangular in cross section, and not square, which allows you to turn them 90 degrees to adjust slightly for different marble sizes.

Initially I was going to drill holes and use pins to mount the far ends of the rails, but