Pretty easy to build. It was surprising that you had to use 3 motors, but I understood after seeing it work! Some of our team members added a paper tutu to make it look more authentic (a paper coffee filter).
Fine design, great for younger kids! One of the teacher's came in with her little girl and she REALLY liked it. The fact that it fell apart and pieces went flying was a bit scary, but I guess it was designed to do that.
Only negative comment is that the gear to change to the explosion sometimes got stuck in between. Not sure how to fix that.