I'm an elementary school teacher of over 20 years and I'm always looking for educational games for my boys. My SIX year old devoured this game in about 3 days! By the last level he was solving multi-step algebraic equations mostly on his own!
I'm blown away. I will have him use the app from time to time so the concepts can be reinforced, but believe me when I say that I won't be forcing him. He was completely engaged the entire time. I had to tell him time was up a few times and to put the iPad away!
I will definitely be recommending this game to my students and their parents. I will look for more "games" from this developer. If they are as good as this one, I will get them all.