I also loved K'NEX. I built so many things, expanded the Big Ball Factory with additional logic gates at the top, got hands on experience playing with gear rati

I also loved K'NEX. I built so many things, expanded the Big Ball Factory with additional logic gates at the top, got hands on experience playing with gear ratios, tower cranes, and built vehicles to race against my brothers down the stairs (of course the K'NEX man had to stay intact!). It was fun building chunks of a big structure and assembling them together, and inevitably having to rebuild a chunk because of some missing pieces. I do wish they built a control system akin to Lego Mindstorms though. Turning motors on and off manually was fine, but I really would have love to to be able to, for example, build my tower crane such that it could rotate via motor, and have separate controls for lowering the bucket and moving the load closer/further from the tower.