Galactic Defense

NNOS Games presents: Galactic Defense: The new game that is free-to-play, but still fun-to-play!

Galactic Defense is a simple 2D arcade-style shooter game built with Python and Pygame. In this game, you control a player that moves horizontally along the bottom of the screen. Your objective is to shoot down incoming enemy ships before they reach you. With a nostalgic vibe reminiscent of classic arcade shooters, Galactic Defense offers fast-paced action and a straightforward gameplay experience.

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Table of Contents

• Features
• Installation
• Assets
• Running the Game
• Game Controls
• Command-Line Options
• Code Overview
• Credits
• Demo

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Features

• Player Movement: Control your spaceship with the left and right arrow keys.
• Shooting Mechanic: Press the spacebar to fire bullets at enemy ships.
• Enemy Behavior: Multiple enemies move horizontally and descend gradually. When hit by a bullet, they reset to a random position.
• Scoring System: Earn points for each enemy hit. Special messages are displayed as you reach certain score thresholds (e.g., "Level 2", "Level 3", etc.).
• Background Music: Enjoy continuous background music (with an option to disable it).
• Debug Mode: Optional debug mode that prints key events and actions to the console.

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Installation

Prerequisites

• Python 3
• Pygame

You can install Pygame via pip:

pip install pygame

Downloading the Code

Clone or download this repository to your local machine. Ensure that you have the following directory structure:

├─ **Version**/
│  ├── assets/
│  │   ├── bgm.mp3
│  │   ├── icon.png
│  │   ├── player.png
│  │   ├── enemy.png
│  │   └── bullet.png
│  └── main.py
└── README.md

Note: The assets folder must contain all the necessary image and audio files for the game to run correctly.

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Assets

The game relies on several asset files located in the assets directory:

• player.png: Image representing the player's spaceship.
• enemy.png: Image used for enemy ships.
• bullet.png: Image for the bullets fired by the player.
• icon.png: Window icon.
• bgm.mp3: Background music file that plays during the game.

Make sure these files are correctly placed in the assets directory.

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Running the Game

Navigate to the project directory in your terminal and run:

python3 main.py

Optional Command-Line Arguments

• --nobgm
  Use this flag to disable the background music.

  python3 main.py --nobgm

• --debug
  Enable debug mode, which prints additional debug information (e.g., key presses) to the console.

  python3 main.py --debug

You can combine options as needed:

python3 main.py --nobgm --debug

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Game Controls

• Left Arrow (←): Move the player's spaceship to the left.
• Right Arrow (→): Move the player's spaceship to the right.
• Spacebar: Fire a bullet.

The game ends when an enemy reaches the bottom of the screen, displaying a "GAME OVER" message.

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Code Overview

The main script (main.py) is structured as follows:

• Initialization:
  The game initializes Pygame, sets up the screen, loads assets, and configures initial game parameters (player/enemy positions, bullet state, etc.).

• Audio:
  The bgm() function loads and plays background music (unless the --nobgm flag is provided).

• Asset Loading:
  The load_and_scale_image() function handles image loading and scaling. Errors in loading assets result in clean exits with informative messages.

• Game Loop:
  The core game loop handles:

  • Event processing (keyboard events for movement and shooting)
  • Player movement and boundary checking
  • Enemy movement and collision detection
  • Bullet firing and collision detection with enemies
  • Score updating and level display based on score thresholds
  • Rendering graphics and updating the display

• Collision Detection:
  The is_collision() function checks for overlaps between bullets and enemy images to determine hits.

• Game Over Handling:
  If an enemy moves beyond the screen's bottom, the game displays a "GAME OVER" message and exits.

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Credits

• Game Development: NNOS Games
• Programming Language: Python 3
• Graphics & Sound: Provided via the assets in the assets directory

Feel free to modify or extend the game as desired!

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Enjoy the game and happy coding!