I gave this to my 4.5-yr-old son for Christmas. I needed to help him put the green base pieces together (and I had trouble with it - even needed to use pliers for one section because it wouldn't pop together!) He immediately filled the first layer with gears, put the crank on and enjoyed spinning all of the pieces together. He didn't want me to build up - I think he liked just the pure flat layer of gears. But after we put it away, he hasn't wanted to play with it since. I think I'll let it sit for a while and will then try to reintroduce it and see if he has renewed interest, but it currently doesn't hold his attention for long. Other kids will likely react differently. I like the idea of this toy - hoping my son starts to like it more later!

I practiced building with this set before introducing it to my students for the school year. The base pieces especially were difficult, some of them I couldn't even make fit unless I forced them! Taking the pieces apart was difficult, too.

My grandson loves building things and creating all sorts of interesting designs and things. This set does not feed that creativity. Limited things you can do with it and the pieces are difficult to attach.