Spintronics! It's a puzzle game where you build mechanical equivalents of electrical circuits. It has capacitors, transistors, inductors, etc. Just got it this past weekend (bought it after the Kickstarter ended) and it's really cool.
I really love the concept and execution of spintronics.
However, having just gotten the two part kickstarter edition, it feels like they left out the … fun? The puzzles feel more like academic exercises than the joy that you get from even simple breadboard circuits that do stuff with lights, motors, speakers etc. I think maybe it needs a few more “output” parts to make the experience engaging.
Spintronics feels like a great teaching tool but not a great game.