JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Resonance Flux - Prototype</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div class="container">
        <canvas id="gameCanvas"></canvas>
        <div id="ui">
            Score: <span id="score">0</span>
        </div>
        <div id="gameOverScreen" style="display: none;">
            <h1>GAME OVER</h1>
            <p>Final Score: <span id="finalScore">0</span></p>
            <button id="restartButton">Restart</button>
        </div>
    </div>

    <script src="script.js"></script>
</body>
</html>

CSS

body {
    margin: 0;
    background-color: #111; /* Dark background */
    color: #eee;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    overflow: hidden; /* Prevent scrollbars */
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    position: relative; /* Needed for absolute positioning of UI elements */
}

canvas {
    display: block; /* Removes potential space below the canvas */
    background-color: #222; /* Slightly lighter than body for contrast */
    border: 1px solid #555;
}

#ui {
    position: absolute;
    top: 10px;
    left: 10px;
    font-size: 1.5em;
    color: #fff;
    text-shadow: 1px 1px 2px black;
}

#gameOverScreen {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgba(0, 0, 0, 0.8);
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    color: #fff;
    border: 1px solid #888;
}

#gameOverScreen h1 {
    color: #ff4d4d; /* Reddish color for game over */
    margin-bottom: 10px;
}

#gameOverScreen button {
    padding: 10px 20px;
    font-size: 1em;
    cursor: pointer;
    background-color: #4CAF50; /* Green */
    color: white;
    border: none;
    border-radius: 5px;
    margin-top: 20px;
}

#gameOverScreen button:hover {
    background-color: #45a049;
}

JavaScript

const canvas = document.getElementById('gameCanvas');
const ctx = canvas.getContext('2d');
const scoreElement = document.getElementById('score');
const gameOverScreen = document.getElementById('gameOverScreen');
const finalScoreElement = document.getElementById('finalScore');
const restartButton = document.getElementById('restartButton');

// --- Config ---
const PLAYER_RADIUS = 15;
const BULLET_RADIUS = 5;
const BULLET_SPEED = 2;
const SPAWN_RATE = 15; // Lower = more bullets (every X frames)

// Use distinct, bright colors
const COLOR_A = 'cyan';    // Player starts as this
const COLOR_B = 'orange'; // Player switches to this

let canvasWidth = window.innerWidth * 0.8;
let canvasHeight = window.innerHeight * 0.8;
canvas.width = canvasWidth;
canvas.height = canvasHeight;

// --- Game State ---
let player;
let bullets = [];
let score = 0;
let frameCount = 0;
let isGameOver = false;
let animationFrameId;

// --- Player ---
class Player {
    constructor(x, y, radius, color) {
        this.x = x;
        this.y = y;
        this.radius = radius;
        this.color = color;
    }

    draw() {
        ctx.beginPath();
        ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2);
        ctx.fillStyle = this.color;
        ctx.fill();
        // Add a subtle outline to make it pop
        ctx.strokeStyle = 'white';
        ctx.lineWidth = 1;
        ctx.stroke();
        ctx.closePath();
    }

    switchColor() {
        this.color = (this.color === COLOR_A) ? COLOR_B : COLOR_A;
    }

    updatePosition(mouseX, mouseY) {
        this.x = mouseX;
        this.y = mouseY;
        // Optional: Clamp position to canvas bounds
        this.x = Math.max(this.radius, Math.min(canvasWidth - this.radius, this.x));
        this.y = Math.max(this.radius, Math.min(canvasHeight - this.radius, this.y));
    }
}

// --- Bullet ---
class Bullet {
    constructor(x, y, radius, color, dx, dy) {
        this.x = x;
        this.y = y;
        this.radius = radius;
        this.color...