After I had killed the required amount of Mollets in level 7, the game glitched and the screen faded to white like 10 times, while at the same time I saw Mollets I had never seen before. When I pressed "countinue," I was on level 19, totally defenseless against the Mollet Army. I had to press "New Game," and when I did, I saw that I still had the money and upgrades from my first game. WUT!?
It seems the laws of physics don't apply in London. Apparently, every object that rolls up a hill is not affected by friction or gravitational attraction. They remain in constant motion instead of slowing down like they're supposed to.