This is an awesome idea, gonna be a good Christmas hobby to build with the kids
Glad I could help.
Another thing that is more expensive but comes "in the box" but is still interesting is "HackPack". Its from the same guy that did the videos on the squirrel ninja obstacle course(s) over a couple of years.
HackPack is for older kids/adults, CrunchLabs is for younger kids. All of them look interesting though. Wish stuff like that was around when I was a kid.