Difficult to assemble. Screws couldn't be screwed with just a screwdriver, had to use pliers to get them screwed all the way in. Second panel, the plastic inserts the screws screw into were loose and just turned with the screws. Had to glue them in place so I could install screws, again having to use pliers. I had to use a magnifying glass to see some of the illustrations, as they were so small. My cats really like it, so I guess it was worth the frustration of putting it together.