const circles = [];

function setup() {
    createCanvas(600, 400);
    strokeWeight(1);
    stroke(0);
}

function draw() {
    background(255);
    circles.forEach((o, i, circles) => {
        fill(o.color);
        circle(o.x, o.y, o.size);
        o.y += 5;
        if (o.y > 420) {
            circles.splice(i, 1);
        }
    });
    text(circles.length, 40, 40);
}

function mousePressed() {
    circles.push({
        x: mouseX,
        y: mouseY,
        color: Math.floor(random(100, 201)),
        size: Math.floor(random(20, 41)),
    });
}