My cat "Diva" started playing and rolling on it when I first started putting it together.  Number stickers had fallen off so I had to check measurements as I put it together.  Also you have to turn and turn forever to get it to tighten up.  I'm concerned about the sturdiness of it, I don't think it's made for a cat over 10 pounds, which that is not Diva, but I'll see.  The seat needs to be bigger.  Would like to see the box with the balls make the holes smaller except for one to slide the balls into.  It didn't take her long to get one out and send it downstairs into the cellar.  Probably should have rated it a 3 star.