My liitle boys first ninjago set and as it was about a third off RRP it seemed good value for the 520 pieces.
The castle measures approx 24cm high by 17cm long and 17cm deep, so is not a bad size. You also get 6 figures 2 ninjas, 2 skeletons and 2 baddies to do battle with.
The model is not especially hard to put togethter with very few fiddly bits and apart from the big spider over the front door(who is 20cm wide by 14cm tall)nothing falls off during play.
There are some good features included like the throne that the wizard sits on that comes off so he can fly it round, you also get a coffin/tomb thingy which you can put a figure in, so that he can rise from the grave so to speak. There is also a jail cell to keep one of the ninjas imprisoned and a table with plate and drink, I presume for the wizard to use as the skeletons probably don't eat much.
On each side of the castle is a tower which rotates and has those flick missiles that lego seem so fond of at the moment,although aiming them is entirely luck based. At the back of the castle is a button you push to release the spider (I say spider although in reality it has only 6 legs) which falls on anyone unlucky enough to be by the bridge or front door.
The figures all come with weapons with the two baddies getting the rarer ones, the wizard gets a flashy looking staff and the big skeleton gets 4 golden weapons(yes he has 4 arms).
All in all a great set either as a one off buy as it includes everything you might need for hours of play, or it makes a great addition to other ninjago/lego sets. My son has also used his kingdom lego models and cobi knights to help attack the castle.
Hope this helps