Quote Originally Posted by JustMe View Post
The max level is 25.
Thanks for info.

I've found that the higher your earnings per day, the better the reward. You might want to try switching them on while doing the challenge and back off after.
I don't think this is true. I had 400m/h (20 energy) and was getting 700m per win when challenges started. Later I lowered income to 60m/h (4 energy) and currently when I win a challenge I get 800M. Maybe it depends on some girl stats (I keep upgrading them) or something else, but not on income on cash panel. I have only 1 girl that can win around rank 17 from time to time, so I can't test winning with another girl.