I've gotten to Lv. 7 several times, it's actually not that hard if you know a few strategies (you can look them up). The basics of it is to look at the row score plus the number of Voltorbs in each row and deduce what's underneath based on that. For instance, if the row score plus the number of Voltorbs adds up to 5, you can safely ignore that entire row since it's nothing but 1's and Voltorbs. Those strategies do help significantly, although you still have to do some guessing, so it's still not that easy. But it's effective enough that you can pretty much max out the Coin Case in about an hour and get whatever you want. I really like this game, they should bring it back.