I was forewarned from reviews about the instructions, and luckily the parts list was accurate, as they were a little hard to follow. Just got muddy in a few parts where matching alphabetical pieces would've helped. The active rescue kitties are 4 months old and terrors on my stairs, I got it to relieve the scratching and cut down on stairwell racing at 4am. They were playing on it as I put it together, and yes, surprisingly the mice on a string are the most popular. I searched for a large, very high tree for these guys a long time. I'm very happy with this choice so far.