W3School TIY Editor

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<style>
canvas {
    border:1px solid #d3d3d3;
    background-color: #f1f1f1;
}
</style>
</head>

var myGamePiece;
var myObstacle;

function startGame() {
    myGamePiece = new component(30, 30, "red", 10, 120);
    myObstacle  = new component(10, 200, "green", 300, 120);    
    myGameArea.start();
}

function updateGameArea() {
    myGameArea.clear();
    myObstacle.update();
    myGamePiece.newPos();    
    myGamePiece.update();
}

function moveup() {
    myGamePiece.speedY = -1; 
}

function movedown() {
    myGamePiece.speedY = 1; 
}

function moveleft() {
    myGamePiece.speedX = -1; 
}

function moveright() {
    myGamePiece.speedX = 1; 
}

function clearmove() {
    myGamePiece.speedX = 0; 
    myGamePiece.speedY = 0; 
}

</script>
<br><br>
<div style="text-align:center;width:480px;">
  <button onmousedown="moveup()" onmouseup="clearmove()" ontouchstart="moveup()">上</button><br><br>
  <button onmousedown="moveleft()" onmouseup="clearmove()" ontouchstart="moveleft()">左</button>
  <button onmousedown="moveright()" onmouseup="clearmove()" ontouchstart="moveright()">右</button><br><br>
  <button onmousedown="movedown()" onmouseup="clearmove()" ontouchstart="movedown()">下</button>
</div>

<p>现在我们的游戏区域有一个障碍物，但当红色方块击中它时仍然没有任何反应。</p>

</body>
</html>