Key Features:

✨ 100 Challenging Levels
- Progressive difficulty from 2x2 to 8x8 grid
- Number of lit cells and observation time increase with level
- From easy to expert difficulty

🎯 Score System
- Score increases with multiplier per level
- Track your high score
- Compete with yourself

💎 Hearts System
- Start with 5 hearts
- Lose 1 heart when selecting wrong cell
- Game over when out of hearts
- Buy more hearts from shop to continue

💡 Hint Power-up
- Use 1 heart to reveal one correct unselected cell
- Help overcome difficult levels
- Strategic usage recommended

🛒 Shop
- 7 attractive heart packages: 5, 12, 25, 70, 150, 300, 600 hearts
- Larger packages = better value (save up to 40%)
- Popular and best value packages are marked
- Secure payment via Google Play

🎨 5 Beautiful Color Themes
- Tech Matrix (Default): Neon theme with bright Cyan colors
- Ocean Blue: Cool and calming blue tones
- Forest Green: Natural green theme
- Royal Purple: Elegant purple theme
- Rainbow: Colorful and fun

🔊 Effects & Feedback
- Sound effects: Tap, Success, Failure, Hint
- Haptic feedback when selecting correct/wrong cells
- Toggle sound and vibration in Settings

💾 Auto-Save Game
- Automatically saves progress when leaving game
- Resume saved game when returning
- Never lose progress when closing app

📊 Progress Tracking
- High Score
- Best Level reached
- Total Games Played
- Detailed statistics in Settings

🌐 Multi-Language
- Supports Vietnamese and English
- Easy language switching in Settings
- Fully translated interface

How to Play:
1. Observe the lit cells on the grid (2-4.5 seconds depending on level)
2. Remember the positions of the lit cells
3. Select the lit cells again to complete the level
4. Wrong selection loses 1 heart, game over when out of hearts

Challenge yourself and train your memory today!