Very easy to assemble! Illustrated instructions, nothing to read. I recommend you first lay out the pieces, and the hardware, so you will know which bolt goes where.
There is enough weight to it, that it would not be easy for the cat to knock it over.  I needed our hand truck to move it from the garage.
My rag doll cats didn't go for it (they aren't big on exerting any effort), but my black and white outdoor cat loves it . I bought it for her, as she loves high places, for napping and for safety.
I know it wasn't designed for outdoor use and may not hold up well on my back porch, but the very affordable price has diminished that concern.