Very simple to assemble, nothing missing. Good quality for the price! My kitten loves it he even eats in the top house.  Wish the houses was a little better padded and would have been nice if fabric would have wrapped all the way around boards. But its a great new pad for a very energetic guy. He has plenty to do now for sure! Very study also. I looked around for weeks and this one was the best buy. Wayfair sent it in a delivery van and the delivery guy carried it up to the house. Keep in mind the boxes are very heavy.