Robo Math Age 6 - 8

My son loved this game. He loves robots and solving the math puzzles. But I only give it three stars because he finished it in under two hours (over the course of a few days). Please add more to the game! Division for starters but then a lot more opportunities to practice! Harder levels with more options would be great. As it stands it is not worth the price, however, with more math added it would be great!