My husband had the pleasure of putting this together. He strongly suggests that the company place all the screws and bolts into bags because the box had holes in it and the screws could have all been lost. As it was only 2 were missing but it could have been worse.
Second suggestion is to have the pieces marked. Several of the components are difficult to tell apart and needing to measure the posts was also time consuming as they are all in metric. 
We even watched the video and took notes and it still took all day to assemble. The directions that come with the tree are a black and white drawing but no written instructions. These would make assembly a lot easier and I would have given it 5 stars. 
On the plus side my cats took to it right away. And it looks awesome in my living room.