Easy to assemble. Not meant for cats over 15 lbs. My big cat fills the big play box lol. One problem, one of the legs of the top 3 platforms didnt have its threading so I had to rig it to assemble it to the tree. Still trying to get it to work, but as its only one piece and on the top of the tree its not worth the hassle of sending it all back. Cats love it!! Theyre all 4yr or older cats and were laying on if before I had it finished