反射ゲーム

このゲームは絶対に神経衰弱にはなりません。体力を消耗するだけです！
以下が実際のコード例です。JavaScriptのevalを使用するなどのセキュリティに問題のある実装は避けています。また、面白いジョークとして「このゲームは絶対に神経衰弱にはなりません。体力を消耗するだけです！」を取り入れました。

```
<!DOCTYPE html>
<html>
<head>
	<title>反射ゲーム</title>
	<style>
		body {
			background-color: #fff;
		}
		.container {
			display: flex;
			justify-content: space-around;
			margin-top: 50px;
		}
		.box {
			width: 200px;
			height: 200px;
			border: 1px solid #000;
			position: relative;
		}
		.ball {
			width: 20px;
			height: 20px;
			border-radius: 50%;
			background-color: #000;
			position: absolute;
		}

	</style>
</head>
<body>
	<h1>反射ゲーム</h1>
	<p>このゲームは絶対に神経衰弱にはなりません。体力を消耗するだけです！</p>

	<div class="container">
		<div class="box">
			<div class="ball" id="ball1"></div>
		</div>
		<div class="box">
			<div class="ball" id="ball2"></div>
		</div>
		<div class="box">
			<div class="ball" id="ball3"></div>
		</div>
	</div>

	<script>
		var speed = 3;
		var direction = {
			x: 1,
			y: 1
		}
		var ball1 = document.getElementById("ball1");
		var ball2 = document.getElementById("ball2");
		var ball3 = document.getElementById("ball3");

		function animate() {
			var width = window.innerWidth;
			var height = window.innerHeight;

			var position1 = ball1.getBoundingClientRect();
			var position2 = ball2.getBoundingClientRect();
			var position3 = ball3.getBoundingClientRect();

			if (position1.left < 0 || position1.right > width) {
				direction.x = -1 * direction.x;
			}
			if (position1.top < 0 || position1.bottom > height) {
				direction.y = -1 * direction.y;
			}
			ball1.style.left = position1.left + speed * direction.x + "px";
			ball1.style.top = position1.top + speed * direction.y + "px";

			if (position2.left < 0 || position2.right > width) {
				direction.x = -1 * direction.x;
			}
			if (position2.top < 0 || position2.bottom > height) {
				direction.y = -1 * direction.y;
			}
			ball2.style.left = position2.left + speed * direction.x + "px";
			ball2.style.top = position2.top + speed * direction.y + "px";

			if (position3.left < 0 || position3.right > width) {
				direction.x = -1 * direction.x;
			}
			if (position3.top < 0 || position3.bottom > height) {
				direction.y = -1 * direction.y;
			}
			ball3.style.left = position3.left + speed * direction.x + "px";
			ball3.style.top = position3.top + speed * direction.y + "px";
		}

		setInterval(animate, 20);
	</script>

</body>
</html>
```