Solución Creeper

<meta charset="utf-8">

<canvas width="600" height="400">

</canvas>

<script>
    var pantalla = document.querySelector("canvas");
    var pincel = pantalla.getContext("2d");
    pincel.fillStyle = "lightgrey" //Propiedad
    pincel.fillRect(0,0,600,400) //Funcion


    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.beginPath()
    pincel.moveTo(265,240);
    pincel.lineTo(225,240);
    pincel.lineTo(225,350);
    pincel.lineTo(265,350);
    pincel.fill();

    pincel.fillStyle= "black";
    pincel.beginPath()
    pincel.moveTo(335,240);
    pincel.lineTo(375,240);
    pincel.lineTo(375,350);
    pincel.lineTo(335,350);
    pincel.fill();

</script>