I bought this for my 4 kittens. It [...] was very easy to assemble. They immediately went to investigate and within a day, one kitten had taken the top level as his own. We put it by a window and they love to gaze out and watch the world go by. They also like to go in and out of the bottom level and peek out from the holes.It is hard for the cat at the top to get down when another cat is sitting on the level below and it would be nice if the other levels were closed in like the top one to prevent a fall. They all use it and sleep on it regularly, Sometimes disagreeing about who gets the top. All in all, a great product, especially for more than 1 cat and at a great price. Similar ones at stores are a lot more expensive and then you have to get it home too. [...]