My Take
My overall opinion on this resource as a teaching tool is that it is wonderful. It turns teaching into a game, and has a bunch of different levels of math for all ages, including those in middle school and college. My only gripe is that it sometimes is so difficult, and takes so long, that students lose attention.
How I Use It
I used this to learn different types of math in a gamified way. I think it is a wonderful tool to use for children because it can keep their attention.