You know, I always remembered the Wintergatan Marble Machine and occasionally idly wondered why I never again saw anything new from someone who must surely be incredibly talented. This explains that.
Here's something of his that's entirely unrelated to marbles, it's a handheld modular synthesizer of his own design with an analogue fretboard that he calls a "modulin": https://www.youtube.com/watch?v=QaW5K85UDR0