My suggestion: At the beginning of the game the child has to solve a few math problems. Help him not doing and encourage it more, sometimes omit an duties at. Then the initial difficulty is not so high. It is not supposed to be equal discouraged. In a later passage, it can then still increase.
In any case, it is a linear-scale game with a beginning and an objective. This spurs on the one hand, but can also tempt the intermediates with impatient haste to "do" because the tasks used only as a means to an end. They are not the goal itself. If you prefer to specifically train only certain weaknesses with your child, there are other games, for example, "flash Computing".
During the game you can move freely on the island, as long as you have earned enough money for the donkey taxi. Oh, and the circus can be a demonstration of calculation methods. Because there are several animal artists to show what there is for ways to solve an arithmetic problem.