It wasn’t too hard to put together.  I did put the perches on the wrong side and had to open that side to complete them, but otherwise no issues.  Took me about 2 hours to put together - mainly because all the holes are not pre-drilled.  It’s sturdy but easy to move, too.  My cat was a little skeptical initially but has seemed to enjoy playing in it thus far.  So far would recommend and would purchase again.