>>11618814
>The fun is in watching the marbles go around in a silly way?
This and building the tracks.
It's fun building the tracks and making your own, making sure everything works. The connecting systems of the support structures are easy to understand and make custom changes. I had an older set without the cheater walls on the corners, which are more difficult to get the correct speed for and prone to have the marbles fall off.
If you have several marbles going around at the same time, it makes a satisfying humm noise, as a kid I'd make the tracks where the marbles end up in around the same spot as the start, put them back on the start by hand and watch them roll around continously. It probably activates a similar autistic part of the brain as something like fidget spinners do, I think. I wish I would have had some sort of elevator system to make it easier.
There's several sets that are compatible with each other, it's a really good system. I still occasionally watch marble runs on youtube, it's really cool seeing someone who's bought like a dozen boxes of track make a gigantic rollercoaster through their house.