Set turn ratio before hitting flag. You will probably want to turn on Turbomode or run it as https://turbowarp.org/921811003?turbo Experiment with different turn ratios. I like 3.0 and -0.3, -2.0 and -1.2, 2.2 and 0.7, -4.25 and 0.6 Comment below with your favorites. Press Space to hide or show the square and the circle. try pi (button)
I started with crkcity's easy to modify project and replaced a circle with a rectangle, changed the drawing to use pen (which is based on another crkcity project of the same type). Inside you could change the costume used by the circle2 sprite to change how the line is drawn.