Have you actually tried playing the mini games yourself or did you just assume it worked?
I think i might know a few reasons as to why people are finding the minigames so difficult:
1. RenPy isn't the best when it comes to counting down seconds. I've noticed a slight delay between ingredients (but the timer keeps ticking).
2. The voice actress isn't saying the ingredients instantly. There is a slight delay for certain ingredients before she says the first letter (crucial moments).
3. Milk, flour, and sugar all look deviously similar when making split second decisions. And in the latter half of the game, a single mistake is a instant game over.