I need an algorithm. I have a circle that goes across the screen and right now the bigger the circle is, the faster it moves, because I move based on the length. What I want though, is for the circle to move slower as it gets bigger, as if perhaps it weighs more. Since I have length handy, I want an algorithm based on the length where the move_amount gets lower, or slower and vice versa gets faster as the circle gets smaller. Any ideas or directions to point me in ?