Attention: the game leaderboard is a lie! Your score rolls over at 4.3 billion, and then the game breaks. That's why the highest score is only 4.29 billion. It isn't that hard to write code that continues to add orders of magnitude ad infinitum!
What the hell?! The game broke because I was getting super huge points, like above 10 billion. I still had 14 seconds left when obtained the score you see on the leaderboard. Is your program incapable of calculating that high? If so, consider yourself pwn'd mr. programmer of this.