hello, I relay like your game. But the Snout Brooch is may by too good:
is probably the exponential grow:
if you start with t coin, the second effect after x*10 second add t*(1.0822)^x, so every 292 second or 4 minute and 52 second (4:52) multiply by 10 (a liter more) the coin.
This can look like a small increment but if you start with 1 coin after 1 hours you and up whit more than 10^20 and after "only" 5 hour whit 10^100 coin (the atom in the universe are 10^88).
I don't now how to fix this in general if you have some exponential whit bases b, the log_{b}(10) is how many time need to pas before the coin x10, if can help. Good luck for the game, is very fun.