let a =10;
let x=10;
let y=10;
let r=50;
function setup() {
createCanvas(500,500);
colorMode(HSB,360,150,50);
//background(120);
}
function draw(){
a+=20;
noStroke();
fill(random(360),200,100);
r=random(350,150);
y=r*sin(radians(a))+250;
x=r*cos(radians(a))+250;
ellipse(x,y,10,10);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.1.9/p5.min.js"></script>