Negative values – Winterbells Review

I was under the impression that the birds double your score. After I get the next bird after 5 quintillion, the values switch to negatives, and doesn't count as your high score. And after two more birds, it's turns back to positive, but it's a value less than 5 quintillion. This process repeats and I can never get the high score I want. Is this a mistake? Or can someone explain the math behind it so I know what to do. It's hard to count the exact value at the top left corner when you're playing the game.
Review by sheranp on Winterbells.