Click dots and drag to change the curve. Each dot represents a point and the color change on the curve represents the amount of weight to each point. An updated version where you can add points is here: https://scratch.mit.edu/projects/838073537/
Credit to @Collin_The_Newmaker for showing me this video and giving me the idea. I used the polynomial representation of the Bézier curve from the video below to create this project. https://www.youtube.com/watch?v=aVwxzDHniEw&t=265s