A rolldown game, neat.

Balls on IPDB look like ping pong balls, but I'm not sure. Based on the layout I'd suspect that it didn't use standard 1 1/8" bingo balls, but it's hard to say with only a single example available to review. Since the metal posts would not offer much bounce for a metal ball, I'd guess that a lighter ball (like a ping pong ball) would need to be used for play action. The big question would be if they had enough weight to activate the switches in the holes. Perhaps a marble would be a better fit, if not.

Electrically, it should be, perhaps, even simpler than Hi-Hand. There might not be any relays.