I barely had the parts out of the box before my cats swarmed it. After only the first layer was secured, 2 of my 6 cats were already playing with it. Now that it's built, all 6 have been on and off of it. Very simple to put together, everything you need is already in there. Yes, it will wobble slightly but the base is so large it's nearly impossible to tip over, even with all 6 of mine on it and playing roughly. I am SO glad I purchased this tower for my cats. Even my lazy 12 pound cats is having a blast!