The user wants me to build a single-page top-down alien shooter game using Phaser.js. Let me plan this out:

1. Load phaser.min.js from the current directory
2. Build a complete game with:
   - WASD movement
   - Mouse aim and click to fire
   - Waves of advancing aliens
   - Health system
   - Score tracking
   - Increasing difficulty
   - All procedurally generated graphics (no external assets)

I'll need to use Phaser's Graphics objects to draw everything - the player, aliens, bullets, explosions, etc.

Let me design the game:

**Player:**
- Drawn as a triangular ship/tank shape using Graphics
- WASD movement
- Rotates to face mouse cursor
- Fires bullets on click or automatically

**Aliens:**
- Different types drawn procedurally (circles, blobs, etc.)
- Spawn in waves from edges
- Move toward player
- Increasing speed and numbers each wave

**Bullets:**
- Simple small circles/lines from player in aim direction

**HUD:**
- Health bar
- Score display
- Wave number

**Difficulty:**
- More aliens per wave
- Faster aliens
- Aliens shoot back (maybe in later waves)

Let me write this all in one index.html file using Phaser 3.

Key technical details:
- Use `this.add.graphics()` for procedural drawing
- Generate textures using Graphics objects and `generateTexture()` method
- This way we can create texture keys that sprites can use

Let me structure the game:

```javascript
// In preload, generate textures using Graphics:
// - player texture (triangle/ship shape)
// - alien textures (different shapes for variety)
// - bullet texture (small circle)
// - explosion frames
```

Let me write the complete game now.

The user wants a top-down alien shooter game built with Phaser 3, all in a single index.html file. Let me plan out the features:

1. **Player**: Top-down view, moves with WASD, aims with mouse, fires with click
2. **Aliens**: Waves of advancing aliens, increasing difficulty
3. **Graphics**: All procedurally generated using Phaser's graphics API (no external images)
4. **Health system**: Player has health, takes damage when aliens reach them or shoot
5. **Score**: Track kills/points
6. **Increasing difficulty**: More aliens, faster, tougher waves over time
7. **Bullet mechanics**: Player shoots bullets toward mouse cursor

Let me build this step by step:

- Player ship (drawn as a geometric shape - triangle/pentagon pointing toward mouse)
- Aliens (drawn as various geometric shapes - circles with tentacles, etc.)
- Bullets (small bright shapes)
- Background (stars, dark space)
- HUD (health bar, score, wave number)
- Particle effects for explosions (procedural)

Let me write a comprehensive game. I'll use Phaser 3's Graphics API to create textures at runtime.

Key design:
- Boot scene: Generate all textures procedurally using Graphics objects, then create textures from them
- Main game scene: Use the generated textures in sprites

Game mechanics:
- WASD movement
- Mouse aim (player rotates toward mouse)
- Click/hold to fire
- Aliens spawn in waves from edges
- Aliens move toward player
- Some aliens shoot back
- Collision detection
- Health decreases on alien contact or hit
- Score increases on kills
- Waves get harder: more aliens, faster, more HP, shoot more frequently

Let me code this up thoroughly.