README updates

Author: olegbespalov

README.md

@@ -6,24 +6,28 @@
   ![CI](https://github.com/olegbespalov/rust-in-space/workflows/CI/badge.svg)
 </div>
 
-A classic space shooter game built with Rust and Macroquad. Navigate through space, destroy asteroids and enemy ships, collect powerups, and try to achieve the highest score!
+A mission-based space shooter game built with Rust and Macroquad. Complete missions, destroy enemies, collect resources, and progress through increasingly challenging levels!
 
 ## Features
 
-- **Classic Space Shooter Gameplay**: Rotate and thrust your ship to navigate through space
-- **Asteroid Destruction**: Break large asteroids into smaller fragments for bonus points
-- **Enemy Ships**: Battle enemy ships that shoot at you
-- **Powerups**: Collect health and rapid fire powerups to survive longer
+- **Mission-Based Gameplay**: Complete objectives across multiple levels with increasing difficulty
+- **Classic Space Shooter Controls**: Rotate and thrust your ship with smooth engine mechanics
+- **Asteroid Destruction**: Break large asteroids into smaller fragments, with rare asteroids dropping valuable loot
+- **Enemy Ships**: Battle enemy ships that track and shoot at you
+- **Loot System**: Collect scrap, rare metals, health packs, and weapon boosts
+  - **Magnet Effect**: Loot items are automatically attracted to your ship when nearby
+  - **Animated Loot**: Items rotate and drift realistically in space
+- **Resource Management**: Track scrap (ordinary currency) and rare metals (premium currency)
 - **High Score System**: Your high score is automatically saved and persists between sessions
-- **Lives System**: Start with 3 lives and collect health powerups to extend your survival
+- **Lives System**: Start with 10 lives and collect health packs to extend your survival
 
 ## Controls
 
 - **Left Arrow**: Rotate ship counter-clockwise
 - **Right Arrow**: Rotate ship clockwise
-- **Up Arrow**: Thrust forward
-- **Space**: Shoot bullets
-- **Enter**: Start game (from menu) or return to menu (from game over screen)
+- **Up Arrow**: Thrust forward (with smooth engine ramp-up)
+- **Space**: Shoot bullets / Launch mission (from briefing screen)
+- **Enter**: Start game (from menu) / Next mission (from success screen) / Return to menu (from game over screen)
 
 ## Installation
 
@@ -72,20 +76,52 @@ The pre-commit hook automatically runs the same checks as CI before each commit.
 
 ## Game Mechanics
 
+### Mission System
+
+The game features a mission-based progression system:
+- **Briefing Screen**: View mission objectives before launching
+- **Mission Objectives**: Each mission requires completing specific goals:
+  - Destroy a certain number of enemies
+  - Collect a certain amount of scrap
+- **Mission Success**: Complete objectives to progress to the next level
+- **Progressive Difficulty**: Missions become increasingly challenging with more enemies and asteroids
+
 ### Scoring
 - **Asteroids**: 100 points each
 - **Enemy Ships**: 500 points each
 
-### Powerups
-- **Health Powerup** (Green circle): Adds one extra life
-- **Rapid Fire Powerup** (Purple circle): Temporarily increases fire rate (lasts 6 seconds)
+### Loot System
+
+Loot items drop from destroyed asteroids and enemies:
+
+**From Regular Asteroids:**
+- **Scrap** (40% chance): 1-3 scrap pieces
+- **Rare Metal** (5% chance): 1 rare metal piece
+
+**From Rare Asteroids** (10% chance to spawn, always drop loot):
+- **Rare Metal** (50% chance): 2-4 rare metal pieces
+- **Scrap** (30% chance): 5-9 scrap pieces
+- **Health Pack** (10% chance): Restores 1 life
+- **Weapon Boost** (10% chance): Rapid fire for 10 seconds
+
+**From Enemy Ships:**
+- **Scrap** (30% chance): 5-9 scrap pieces
+- **Health Pack** (10% chance): Restores 1 life
+- **Weapon Boost** (5% chance): Rapid fire for 10 seconds
+
+**Loot Mechanics:**
+- Items drift and rotate in space for visual appeal
+- **Magnet Effect**: When within 150 units of your ship, loot is automatically attracted to you
+- Items are collected on contact with your ship
 
 ### Gameplay
 
-- Start with 3 lives
+- Start with 10 lives
+- Complete mission objectives to progress
 - Destroy asteroids to break them into smaller pieces
-- Enemy ships spawn periodically and shoot at you
-- Powerups have a 10% chance to drop when destroying asteroids
+- Rare asteroids (10% spawn chance) have distinct appearance and better loot
+- Enemy ships spawn based on mission configuration and track your position
+- Collect scrap and rare metals for future upgrades (coming soon)
 - Colliding with asteroids or enemy bullets reduces your lives
 - When all lives are lost, your score is saved if it's a new high score
 
@@ -95,9 +131,13 @@ The pre-commit hook automatically runs the same checks as CI before each commit.
 space_game/
 ├── src/
 │   ├── main.rs      # Main game loop and state management
-│   ├── components.rs # Game entities and data structures
-│   ├── systems.rs   # Game systems (wrapping, save/load)
-│   └── draw.rs      # Rendering functions
+│   ├── components.rs # Game entities and data structures (Ship, Asteroid, Loot, Mission, etc.)
+│   ├── systems.rs   # Game systems (wrapping, save/load, mission generation, loot generation)
+│   ├── draw.rs      # Rendering functions
+│   └── resources.rs # Resource management (texture loading)
+├── assets/          # Game assets (sprites, textures)
+│   ├── loot/        # Loot item textures
+│   └── ...
 ├── Cargo.toml       # Project dependencies
 └── highscore.json   # Saved high score (auto-generated)
 ```