Major Game Update: Realistic Planets, Black Hole Catcher, Infinite Mode, Login & Leaderboard

## Overview
This is a major update proposal for "Celestial Catcher v2" to transform the game's visuals, mechanics, and player experience while retaining the core gameplay.

### Features & Enhancements

1. **Replace Colored Balls with Realistic Planets**
- Replace color balls with visually accurate representations of Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
- Use high-quality images or custom canvas rendering for each planet, ensuring unique textures and realistic appearances.
- Update all UI and game logic to reference planets by name.

2. **Black Hole Catcher**
- Redesign the catcher to look like a realistic black hole, featuring event horizon, accretion disk, and gravitational lensing effects.
- Add animated swirling and visual effects for immersion.

3. **Infinite Level System**
- Remove the current sector/level progression.
- Implement endless gameplay: player scores can increase infinitely.
- Dynamically increase difficulty over time via spawn rates, object speeds, and new hazards.

4. **Challenging & Interesting Gameplay**
- Add new obstacles: asteroid belts, rogue comets, space debris, unpredictable planet movements, variable gravity.
- Introduce more power-ups: temporary shields, slow-motion, enhanced score multipliers.
- Make game progressively harder and less predictable as score rises.

5. **Animated Home Page Theme**
- Create a visually dynamic home screen with animated stars, planets, and black holes.
- Use smooth transitions, parallax effects, and engaging background music.
- Ensure the home page is highly attractive and sets the tone for the game.

6. **Login Interface (Google Authentication)**
- Require players to log in with Google before playing.
- Integrate Google Sign-In API, and store user profile (name, avatar, Google ID).
- Ensure seamless authentication flow.

7. **Global Leaderboard**
- Add a leaderboard screen showing global player rankings, scores, and player info (name/avatar).
- Implement backend integration (e.g., Firebase, Supabase, or custom REST API) for storing and retrieving scores.
- Leaderboard updates on game over and at regular intervals.

8. **Preserve Gameplay Experience**
- Retain core "catch planets" gameplay and user flow.
- All enhancements should build upon and not disrupt the established mechanics.

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### Acceptance Criteria
- Realistic planet graphics are used throughout the game.
- Catcher is visually a black hole with animated effects.
- Gameplay is endless, with difficulty scaling over time.
- Home page features animated stars, planets, and black holes.
- Google login is required to play; player info is stored.
- Global leaderboard displays logged-in players' scores and ranking.
- All UI and logic changes are tested and do not negatively impact core gameplay.

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### Additional Notes
- If using external services/APIs, ensure privacy and data security.
- Consider mobile and desktop responsiveness for all new UI elements.