I am having a weird bug where the first "Fattening food" level is purchasable at 70 milk but when bought it immediately plunges the milk to -100. I restarted and waited till I had about 110-115 milk before buying it and it still sent me to -100 milk. I am unsure if I am just missing something or if it is indeed a bug but I have replicated it three times in a row without change.