The pieces are a little too difficult for my 9yo to assemble alone, but had no trouble popping them out and following the instructions. After adding some Elmer's glue, my 4yo kids enjoyed turning the crank and watching the balls

My son had fun assembling this puzzle, but after it was done, the marbles do not flow the way they should. He is a master Lego builder and has put together kits with thousands of pieces, so I'm sure he assembled it correctly. All in all, it was disappointing to get it finished and not have the mechanism work. I would not buy this again.

This was a blast to assemble! Kept me busy for hours while putting it together, and is now a cool toy and conversation piece in my living room. Would seriously HIGHLY recommend.

I bought this for my husband for Christmas and he absolutely loves it! He built it the very next morning. It did take about 4-5 hours to build just as advertised, but he loves that kind of stuff so it didn’t bother him at all. It works great as you can see from the video. No pieces broke during the build (which has happened in the past with other kits). This was absolutely with the money and I’m very happy to have purchased it!

Gave to my 17yo son as a gift. He really enjoyed putting it together (took him maybe 2-3 hours). After assembly, it's actually pretty sturdy and works very smoothly

After getting the puzzle all together went to use it with the marbles supplied with the puzzle and marble would not go through the maze. Not sure what part is not working and very disappointed

After two months I grew tired of jigsaw puzzles so I ordered this for something different. Planning on taking my time to construct but on first inspection look well made and interesting. Would buy again without hesitation.