@gmacpro Due to the design it got a bit hidden. But if you let R do your work you'll soon see what's hidden. Spoiler Watch out for the two low balls, one is for R to follow the path and the other to release R.
@Jóh - I've won so I know what the visible balls are for. 'Bit Hidden' is an understatement as I had a hard time even seeing it in MekoStudio.
Two problems detracted from my enjoyment. One ball fell spontaneously. R failed to nudge a ball that made me question my gameplay.
Great logical level. Time to figure out how to get on the bridge, cool this trick with Zapper. Congratulations for your work.