We have mixed reviews for this one. Our cat wanted nothing to do with this once we set it up. It was very wobbley when he jumped on it and the ramp kept coming undone when he tried to climb it. We were definitely a little  disappointed with the stability. Our kitten on the other hand, really likes it. He doesn't climb on it much, I think even he feels like it is unstable but he likes to jump in the cube and play with the balls.  Overall I would say not suitable for cats but if you have a playful kitten they will probably be happy.