I bought these both for my nephews, who live in a different country.
Firstly - there are no big metal parts or batteries and these were "ok" by TSA, in both check-in and baggage, in case someone needs this info.
Secondly - the quality. These are made of plastic. At first glance, since the parts are very light, it seems cheap, but I assure you, it's not. My nephews dropped the parts multiple times, fitting wrong parts forcibly, and pulling the strings to their limits. Even the smallest, thinnest latches are very durable. I hope that these will be passed down to the younger siblings, atleast, if not next generation.
Thirdly, and most importantly - the experience - it was the best. Its not just a great learning game, but when the kids were not doing the puzzles, they started making random circuitry using imaginative arrangement of the parts. I think that is the best part of any game, which lets kids use their imagination, as much as they desire.
There are other great things which have already been said in other reviews, so I'll keep it short.
And THANK YOU!!!! to the Upper Story Team, please keep doing what you're doing.
I'll be back for more.
