Let alone grow? What exactly grew? New ninjas are added with extremely overpowered abilities so older ones become obsolete quickly. The "story mode" has not been changed in an extremely long time, even though it's just a slug half the time waiting for you to hit x or y levels to continue at all, and pvp? Pay more and you will win. So again, besides adding new, overpowered ninjas, and adding a few more systems where you can gain power, what needs so much money from the playerbase? This does not seems to be that much of a powerhog of a game that you'd need it to be pay to win.