I remember Pizza Tycoon having copy protection based on pizza recipes (for which I didn't have the recipe booklet, for usual reasons). In the early days of your pizzeria, people would only want the classics and if you couldn't make them, you struggled hard. Somehow, I've managed to power through (probably easy difficulty or something) and as soon as you build up connections to the mafia, people would gladly eat the most abhorrend pizzas the world has ever seen (I vividly remember an all-plum pizza I've created, it was beloved beyond any reason).