Obliterate EarthAI · Claude 3.5

Core Game Loop and Mechanics

Obliterate Earth is a physics-based destruction game where players systematically destroy a rotating planet by launching weapons from orbit. The core gameplay loop consists of:

1. Weapon Selection: Player chooses between three weapon types (Missile, Nuke, Asteroid)
2. Weapon Launch: Player taps/clicks anywhere on screen to spawn the selected weapon at a fixed orbital distance
3. Weapon Flight: Weapon locks onto Earth's current center of mass and travels toward it
4. Impact & Destruction: Weapon explodes on contact, carving out a circular chunk of the planet
5. Mass Recalculation: Planet's center of mass instantly recalculates, shifting its rotation pivot
6. Victory: When planet mass drops below 1%, trigger epic destruction sequence

What makes it compelling:

• Satisfying visual feedback with each impact (explosions, particles, screen shake)
• Strategic weapon choice based on desired destruction pattern
• Dynamic physics where the planet's behavior changes as you destroy it
• Clear progression indicator (mass percentage) driving toward victory
• Immediate, visceral destruction with no waiting or resource management

Starting Scope

First Implementation (Minimal Viable Product):

• Single rotating Earth in center of screen
• Three weapon types with distinct properties (size, speed, explosion radius)
• Weapon selection UI at bottom of screen
• Click/tap to spawn weapons at orbital distance
• Collision detection and circular explosion masking
• Real-time center of mass recalculation
• Mass percentage display
• Basic particle effects on impact
• Screen shake on explosions
• Victory condition at <1% mass remaining
• Victory screen with restart button

Future Enhancements (Post-Launch):

• Multiple planets/celestial bodies with different properties
• Weapon upgrades or modifications
• Combo system for rapid successive hits
• Score tracking and leaderboards
• Sound effects and background music
• More elaborate particle systems
• Weapon trails and visual effects
• Different planet textures/themes
• Challenge modes (time limits, weapon limits)

Game Perspective

Fixed-screen perspective with a centered, rotating planet. The camera is stationary, viewing the planet from a 2D orthogonal angle. All action takes place on a single screen with no scrolling. The planet rotates in place while weapons approach from the edges.

Game World and Level Design

Single Level Design:

The game takes place in deep space with a starfield background. At the center of the screen sits Earth - a circular planet with recognizable continents and oceans rendered procedurally.

Planet Specifications:

• Initial size: 200px diameter circle
• Starting appearance: Blue oceans with green/brown landmasses
• Rotation speed: 0.01 radians per frame (slow, visible rotation)
• Position: Screen center initially, shifts as mass changes

Orbital Zone:

• Weapons spawn at 300px radius from current screen center
• Spawn position determined by click/tap location angle
• Creates a clear "orbital bombardment" feel

Space Environment:

• Dark background (#0a0a15 or similar)
• Subtle animated starfield for depth
• No obstacles or other celestial bodies in first version

Technical Implementation:

• Hidden canvas (400x400px) stores unrotated planet pixel data
• Visible canvas renders rotated planet with proper center-of-mass offset
• All collision detection happens in local space on hidden canvas
• Explosions use destination-out blending to carve transparent holes

Edit Mode Design

Editable Properties:

1. Weapon Properties (per weapon type):

   • Explosion radius (10-100px range)
   • Movement speed (1-10 pixels per frame)
   • Visual size multiplier (0.5-2.0x)
   • Particle count on impact (10-50 particles)
   • Screen shake intensity (0-20 pixels)

2. Planet Properties:

   • Initial size (100-300px diameter)
   • Rotation speed (0.001-0.05 radians per frame)
   • Starting color scheme (ocean color, land color)
   • Victory threshold (0.5%-5% mass remaining)

3. Gameplay Properties:

   • Weapon spawn distance (200-500px from center)
   • Particle lifetime (0.5-3 seconds)
   • Screen shake duration (100-500ms)

4. Visual Properties:

   • Background color
   • Star density (0-200 stars)
   • UI color scheme

Constraints:

• Explosion radius must be at least 5px (prevent invisible impacts)
• Planet size must be at least 50px (ensure playability)
• Rotation speed capped to prevent disorienting motion
• Victory threshold minimum 0.1% (ensure game can be won)
• Weapon speed minimum 0.5 (ensure weapons reach planet)

Edit Mode Interface: Simple property panel that appears when toggling edit mode, with sliders and color pickers for each editable value. Changes apply immediately to demonstrate effect.

Control Design

Mobile (Touch) Controls:

• Weapon Selection: Tap one of three weapon buttons in bottom UI panel
• Weapon Launch: Tap anywhere on screen (outside UI area) to spawn selected weapon at that angle from planet center
• Restart: Tap restart button on victory screen

Desktop (Mouse/Keyboard) Controls:

• Weapon Selection: Click one of three weapon buttons in bottom UI panel, OR press keys 1, 2, 3 to select Missile, Nuke, Asteroid respectively
• Weapon Launch: Click anywhere on screen (outside UI area) to spawn selected weapon
• Restart: Click restart button on victory screen, OR press R key

Control Implementation Details:

• Track mouse/touch position to determine spawn angle
• Calculate spawn position: angle = atan2(mouseY - centerY, mouseX - centerX), then spawnX = centerX + cos(angle) * spawnRadius
• Prevent weapon spawning when clicking UI elements
• Visual feedback: highlight selected weapon button
• No complex input schemes needed - simple point-and-click/tap interface
• Clear input state on window blur to prevent stuck states

Art Style and Visual Theme

Overall Style: Dark sci-fi arcade aesthetic with a retro-modern fusion. Clean geometric shapes with glowing accents and particle effects. Emphasis on satisfying destruction visuals.

Color Palette:

• Space Background: Deep navy/black (#0a0a15, #050510)
• Stars: White with subtle twinkle (#ffffff, 50-80% opacity)
• Earth Ocean: Rich blue (#2b5f9e, #1a4d7a)
• Earth Land: Green/brown continents (#3a7d44, #8b6f47)
• UI Elements: Cyan/electric blue accents (#00d9ff, #0099cc)
• Explosions: Orange-yellow-white gradient (#ff6600 → #ffcc00 → #ffffff)
• Particles: Bright orange/yellow with glow (#ff8800, #ffdd00)

Asset Approach:

• Planet: Procedurally generated on hidden canvas (code-rendered continents using Perlin-like noise or random blob shapes)
• Weapons: Simple geometric shapes rendered with code (circles/ovals with gradient fills)
• UI: CSS-styled buttons and text with sci-fi font
• Particles: Code-rendered circles with radial gradients
• Explosions: Code-rendered expanding circles with alpha fade
• Background: Code-rendered starfield with random positioned dots

Visual Consistency:

• All elements use smooth gradients and glowing effects
• Consistent line weights for UI elements (2-3px)
• Unified color temperature (cool blues for UI, warm oranges for destruction)
• Minimalist geometric approach throughout

Technical Rendering:

• Use Canvas API for all game rendering
• CSS for UI overlay styling
• Radial gradients for glows and depth
• Alpha blending for particle effects
• Screen shake via canvas transform

No generated assets needed - entire game can be rendered with Canvas API and CSS, keeping file size minimal and ensuring instant loading.