Zero Below Zero

Don’t let the cute graphics deceive you - this game is HARD.
It’s so difficult, that if you get a perfect score on the free levels, you get the rest of the levels for free.
The goal sounds easy - all you have to do is make each circle at least zero. The trouble is there are gazillions of moves you can make, and just one will give you a perfect score.
Oh, and there are no hints.
There are also no ads, subscriptions, tracking, or anything else you wouldn’t want. If you can’t achieve a perfect score on the free levels, you can always admit defeat and pay to unlock the other levels ;)
This game is inspired by the dollar game maths puzzle as seen on Numberphile. Don’t expect that to help you though - Zero Below Zero has been made much more difficult!