Was good and addictive in the beginning but then when the money figures to upgrade becomes billions and trillions it's hard to understand what's going on. Feels should have never downloaded this game. Just wasted my time because even if I can upgrade I don't want to count after 990 trillion.its not hard to collect coins trillion with 10 mines but beyond that I don't want to play anymore because I don't know how to count after zillion. Very stupid idea to make value so high whoever came up with.