I liked the game. I still have to crack this one, but This time I could make it. It was fun, and the music, one of the most important things to me, was really good.
I tried it myself. Now I can say, why you got back to the mainmenu: You made the value of the pizzas you have left so high that it was to big to be stored as an integer. So it was set to 0. That means you died and so you got back to the mainmenu :)