Assembly was easy enough, and all things were included which was really helpful. The middle and top tiers aren't very big, but I have a runt cat, so he doesn't need a whole lot of space. More coordinated cats would be able to jump around on it I think. 
The only problems are that 1-when he tries to play with the dangly he slips, so it's best to have it on carpet or a rug (which is also easily fixed)! And 2- the top tier is a tad wobbly.
Overall it's a really great buy, Runty loves it!

Pros: Easy assembly; plenty of scratching surface; good play area; tools included
Cons: Kitten slips when playing, unless it's on carpet or rug. 

Pros:  Easy assembly; plenty of scratching surface; good play area; tools included
Cons:  Kitten slips when playing, unless it's on carpet or rug.