My son helped put this together in just under 1 hour.  All of my cats have been exploring the tower and trying out the platforms.
All but one of my cats is large so I think the ramp is not necessary.  I may remove it.  As one other reviewer stated, the fabric on the platforms could be a little thicker for comfort.  It does appear, however, that the fabric will last for quite a while.  I am considering buying another tower from this manufacturer and of course from Wayfair.