This is took me played 5 days since I finally got purchased all upgrades, and I guess only level up some characters? I wasn't expecting because this is, honestly... endless.
By the way, there also helpful to delete save file, i'm assuming there is Local Application Data (%localappdata%), and there's folder name Rina_Clicker.
Yeah, I know this will start over at the beginning, but the game is good too!