"I helped my 5 year old son get the loose parts built, then left him with the instructions and remaining pieces. Aside from one piece in the wrong spot, he did amazingly well.
After getting everything built, we attached everything to an extra base plate we had kicking around. Afterwards, I dug around in his LEGO box, and built a mini-base for Kai, using a mish-mash of parts (none of which was Ninjago), but was a great addition.
We also grabbed some extra lightsaber handles, and attached the wooden poles for practice fights.
He's had it for 2 days, and hasn't put it down. Best $15 I've spent all year."