Not Today! 🎮

A browser-based arcade shooter game where you defend your base against waves of alien invaders using light projectiles.

🎯 Game Overview

Not Today! is a fast-paced defense shooter where mysterious aliens approach your base from above. Your mission: eliminate them before they reach the ground and damage your defenses. Each alien requires 5 precise hits to be destroyed, testing your accuracy and reaction time under pressure.

🕹️ Gameplay

• Control your character using keyboard inputs (WASD or Arrow keys)
• Shoot light balls upward to hit descending aliens
• Destroy invaders before they reach your base (5 hits each)
• Protect your base - each alien that reaches the ground reduces your base life by 5%
• Score points for every alien destroyed
• Track your high scores across play sessions

🎮 Controls

Key	Action
A / ←	Move Left
D / →	Move Right
W / ↑	Shoot Light Ball
Pause	Pause/Resume Game
Quit	Exit to Main Menu

🛠️ Technical Implementation

Core Technologies

• Vanilla JavaScript - Pure JS implementation with no frameworks
• DOM Manipulation - Dynamic element creation and positioning
• CSS3 - Styling and visual effects
• HTML5 Audio API - Background music and sound effects

Game Architecture

Object-Oriented Design

The game uses ES6 classes for clean, modular code:

// Three main game entities
class Prof { }        // Player character with movement and shooting
class Invader { }     // Alien enemies with AI movement and collision
class LightBall { }   // Projectiles with automatic trajectory

Game Loop

• 60 FPS game loop using setInterval(gameLoop, 1000/60)
• Collision detection system for projectile-enemy interactions
• Spawning system generating aliens at 2-second intervals
• Life management tracking both enemy health and base integrity

Key Features

• Collision Detection: AABB (Axis-Aligned Bounding Box) algorithm for precise hit detection
• Perspective Scaling: Enemies grow larger as they approach (simulating depth)
• Projectile Physics: Light balls shrink as they travel upward
• LocalStorage Integration: Persistent high score and last score tracking
• Audio System: Toggle-able music and sound effects
• Pause Mechanism: Full game state pause/resume functionality

Code Highlights

Dynamic Spawning

function invaderSpawn() {
    let randomX = Math.floor(Math.random() * 640) - 320;
    let newInvaderObj = new Invader(randomX);
    invaderArr.push(newInvaderObj);
}

Collision Detection

if (invader.x < lightBall.x + lightBall.width &&
    invader.x + invader.width > lightBall.x &&
    invader.y < lightBall.y + lightBall.height &&
    invader.y + invader.height > lightBall.y) {
    invader.life--;
    // Handle collision...
}

🎨 Features

Game Mechanics

• ✅ Progressive difficulty with continuous alien spawning
• ✅ Multi-hit enemy system (5 hits per alien)
• ✅ Base health system with visual indicator
• ✅ Score tracking with formatted 6-digit display
• ✅ 3-second countdown before game start

User Interface

• ✅ Start screen with score display
• ✅ In-game HUD showing current, last, and high scores
• ✅ Real-time base life indicator
• ✅ Game over screen with results
• ✅ Music and SFX toggle controls

Polish

• ✅ Background music with loop functionality
• ✅ Sound effects for shooting, explosions, and game events
• ✅ Quit confirmation dialog
• ✅ Persistent data storage using localStorage
• ✅ Smooth animations and visual feedback

📁 Project Structure

not-today/
├── index.html              # Main HTML structure
├── style.css               # Game styling
├── script.js               # Main game logic (provided code)
├── classes/
│   ├── Prof.js            # Player class
│   ├── Invader.js         # Enemy class
│   └── LightBall.js       # Projectile class
└── assets/
    ├── img/               # Game sprites and graphics
    │   ├── prof-stable.png
    │   ├── prof-hands-up.png
    │   ├── ground-alien.png
    │   ├── light-ball.png
    │   └── enemy-explosion.png
    └── audio/
        ├── music/         # Background tracks
        └── fx/            # Sound effects

🚀 Getting Started

1. Clone the repository

   git clone https://github.com/yourusername/not-today.git

2. Navigate to the project directory

   cd not-today

3. Open in browser

   # Simply open index.html in your browser
   # Or use a local server:
   python -m http.server 8000
   # Then visit http://localhost:8000

🎯 Game Logic Flow

Start Screen → Countdown (3s) → Game Active
    ↓                              ↓
High Score                    Spawn Aliens
Last Score                    Player Movement
Music Toggle                  Shoot Projectiles
                              Collision Check
                              Base Life Check
                                  ↓
                            Game Over Screen
                                  ↓
                            Update Scores
                                  ↓
                            Return to Start

📊 Learning Outcomes

This project demonstrates proficiency in:

• JavaScript Fundamentals: ES6+ syntax, classes, arrow functions
• DOM Manipulation: Dynamic element creation and management
• Game Development Concepts: Game loops, collision detection, state management
• Event Handling: Keyboard input, click events, audio controls
• Data Persistence: localStorage API for score tracking
• Array Operations: Managing game entity collections
• Timing Functions: setInterval, setTimeout for game timing
• Object-Oriented Programming: Class-based architecture
• Browser APIs: Audio API, localStorage, DOM API

🎓 Technical Skills Showcased

Skill	Implementation
Algorithm Design	AABB collision detection, spawn randomization
State Management	Game state (start/play/pause/end) handling
Performance	Efficient 60 FPS game loop
User Experience	Responsive controls, visual feedback
Code Organization	Modular class-based structure
Asset Management	Audio and image resource handling

🔧 Potential Enhancements

• Add difficulty levels (spawn rate, enemy speed)
• Implement power-ups (rapid fire, shield, slow-motion)
• Create multiple enemy types with different behaviors
• Add boss battles at score milestones
• Implement combo system for consecutive hits
• Add particle effects for explosions
• Mobile touch controls
• Leaderboard system with backend integration

📝 License

This project is open source and available under the MIT License.

👤 Author

Your Name

• GitHub: @naimozcan
• LinkedIn: LinkedIn

🙏 Acknowledgments

• Game concept inspired by classic arcade shooters
• Built as a learning project to demonstrate JavaScript game development skills

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Note: This game was created as a portfolio project to demonstrate proficiency in vanilla JavaScript, DOM manipulation, and game development fundamentals without relying on frameworks or game engines.