p5.js — exemplo Pong
let paddleY = 200, ballX = 200, ballY = 200;
let bx = 3, by = 3;
function setup() { createCanvas(400, 400); }
function draw() {
background(0);
if (keyIsDown(UP_ARROW)) paddleY -= 5;
if (keyIsDown(DOWN_ARROW)) paddleY += 5;
ballX += bx; ballY += by;
if (ballY < 0 || ballY > height) by *= -1;
if (ballX < 30 && ballY > paddleY && ballY < paddleY+60) bx *= -1;
fill(255);
rect(20, paddleY, 10, 60);
ellipse(ballX, ballY, 15);
}