This was very easy to assemble.This is my kitty's new favorite place to be! 
The only problem I have encountered is that when she gets rambunctious and crazy it tends to slide on my floor. It had scratched my floor so I had to place felt circles on the bottom where the screws made contact with the floor.
This is the only reason I gave it 4 stars. If you place it on carpet you will avoid this problem or use something to cover the screw heads.