The thing is really nice and I do like messing with it but the balls can be hard to move about 30% of the time and they make a horrible sound when you spin the balls in place. Parts of it can also get stuck here and there and it's not really something that I can spend hours messing with because of all the tiny things that make it hard to use. It also will never be 100% solved because of its design there will always be two balls on the wrong side.Addicted!This stumped my 30 year old son. lol. He could do a rubic cube in seconds so I’m waiting to see if he masters itIt was sticky/catchy. Hard to maneuver the moving parts. Gonna hand it off to my grandson. He will probably fiddle with it for awhile.I haven’t had a lot of time to figure it out, it was scrambled when it arrived and I normally like to start backwards to see exactly how it works. The beads have to be perfectly lined up to move them which they are fairly small and hard to line up with the middle piece. I don’t like it as much as I thought I would. My younger kids can’t really figure it out, might be ok for older children.I bought this for someone struggling with dementia in hopes that it would help him like other puzzles are supposed to, but it was too challenging.I didn't realize when I ordered it that there are 4 sets of colored balls, and it is two-sided. I think if the balls were only on one side, it would have been less complicated for him.As a teacher though, this will be a great indoor recess/self regulating activity. The parts move easily and it is sturdier than other puzzles in my classroom.The quality of the build is the only thing i wish was better. Other than that it is an effective brainteaser while completing work tasks or while in the phone.Honestly, I ordered the red one, but recieved blue. I'm not going to go through the hassle to exchange, because I don't want upset my autistic child now that she has it. The puzzle/fidget is a fun little puzzle and was a great addition to our collection of calming toys.A mis hijos no les gusto