Too repetitive
This is a nice idea but the free puzzles are the same in each of the three levels. Once a child has completed them, I doubt they would be interested in doing them over. Kids don't actually have to solve the addition problems since they are presented in the same order each time. First the sum that adds up to 1 is the head, next is the sum that adds up to 2, and so on. It would be more engaging if different problems we're shown each time you play.