Strange level. I was still in the process of figuring out the path when the domino stones started falling and hit the win. I do not want to watch the solution video. Is B supposed to outrun the mechanism?
@GFJ When B pushes the last ball, the domino will fall and hit the win block (it tooks some time) , so your B does not need to outrun the mechanism, just wait.
I finally managed to get B on its way and B was quick enough to push the final ball before the mechanism started itself.