When I got to Red Rush 7s, I couldn't click to put down any more coins. Did it break?
No, it probably means you didn't have past 10 in coin balance. In RedRush7s the coin denomination increases to 10, so your coin balance has to be greater than that to be able to drop one coin. I've gotten feedback on this as well and I have plans to add some sort of tooltip to explain it. Sorry about that experience!