Press R to reset the slider variables, which you can access by pressing the gear icon. You can also reset the variables by pressing the "Reset" button. Press M or press the "Change Music" button to change the music. The music will not change if you don't press M or press the "Change Music button.
Thanks to @griffpatch for the tutorial on how to create this simulation. The boids also go away from your mouse pointer. Don't believe? Turn up the "Range" variable and "Top Speed" variable in settings and put your mouse pointer in one spot. They may turn away from it like they turn away from other boids. Laggy? https://turbowarp.org/1018575175 Slider variables meanings: Top Speed: It is more like the target speed the boid wants to reach. Resolve: The speed it reaches to the top speed. Range: The range a boid has, like it's personal space. Separation: The force used to push away one boid to another, or to push away from the mouse pointer. Cohesion: The amount of boids that are together. Alignment: The amount of boids that travel at the same direction.