We are the proud owners of an Imaginarium Deluxe Marble Race. Tonight, my boys (and the girl, although not directly) asked me to help them build a big Marble Race,following the plans in the instructions.
We built it and as we were doing it, Benjamin pointed out things that he thought wouldn't work. But we kept building. When it was done, we tested it - and a few things didn't work right. They were the ones he mentioned during construction.