Solução do meu Creeper | JavaScript e HTML: pratique lógica com desenhos, animações e um jogo

<!DOCTYPE html>
<html lang="pt-BR">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Desenho</title>
    <style>
        body{
            background: rgb(0, 0, 0);
            font: normal 15pt Arial;
        }
        header{
            color: rgb(0, 0, 0);
            text-align: center;
        }
        h1{
            text-shadow: 1px 1px 1px rgb(25, 253, 4);
        }
        section{
            background: white;
            border-radius: 10px;
            padding: 30px;
            width: 700px;
            height: 500px;
            margin: auto;
            box-shadow: 3px 3px 10px rgba(25, 253, 4, 0.363);
        }
        footer{
            color: white;
            text-align: center;
            font-style: italic;
        }
        canvas {
            padding-left: 0;
            padding-right: 0;
            margin-left: auto;
            margin-right: auto;
            margin-top: 50px;
            display: block;
            width: 600px;
        }
    </style>
</head>
<body>
    <header>
        <h1>Creeper</h1>
    </header>
    <section>
        <canvas width = "600px" height="400px"></canvas>
        <script>
            let tela = document.querySelector('canvas')
            let pincel = tela.getContext('2d')

            pincel.fillStyle = 'black'
            pincel.fillRect(0, 0, 600, 400)  //faz um retangulo     
            pincel.fillStyle = 'darkgreen'
            pincel.fillRect(125, 50, 350, 300)

            pincel.fillStyle = 'black'
            pincel.fillRect(175, 100, 90, 90)

            pincel.fillStyle = 'black'
            pincel.fillRect(335, 100, 90, 90)

            pincel.fillStyle = 'black'
            pincel.fillRect(265, 190, 70, 100)

            pincel.fillStyle = 'black'
            pincel.fillRect(225, 240, 40, 110)

            pincel.fillStyle = 'black'
            pincel.fillRect(335, 240, 40, 110)
        </script>
    </section>
    <footer>
        <p>&copy; LucasCorte</p>
    </footer>
</body>
</html>