# Plan v3: Level System Overhaul

## Summary of Changes Requested

1. **Boss duration affects spawned enemies** - Boss's `duration` setting covers full journey (boss + spawns reaching well)
2. **Keep triangle enemy (basalt_guardian)** - Keep in config but don't use in levels
3. **Separate difficulty levels** - Folder-based: `levels/easy/`, `levels/medium/`, `levels/hard/`
4. **Regenerate all levels** - Using BPMs from bpm.md, evenly distributed, match music duration

## Decisions Made

### 1. Difficulty Level File Structure
**Answer: Folder-based**
```
levels/easy/level1.json
levels/medium/level1.json
levels/hard/level1.json
```

### 2. Boss Duration Propagation
**Answer:** Duration covers boss travel + spawns reaching well.
- If duration=10s and boss explodes at 60% of travel (explodeAt=0.4 means 40% screen width):
  - Boss explodes at 6s
  - Spawns hit well 4s later (at 10s total)
- Spawns use same speed as boss

### 3. basalt_guardian
**Answer:** Keep in config, just don't use in levels

### 4. Level Intensity Curve
**Answer:** Evenly distributed for now

## Music/Level Reference

| Level | Music | Duration | BPM | Half BPM | Double BPM |
|-------|-------|----------|-----|----------|------------|
| 1 | lvl1.wav | 44.8s | 126 | 63 | 252 |
| 2 | lvl2.wav | 42.3s | 126 | 63 | 252 |
| 3 | lvl3.wav | 55.8s | 140 | 70 | 280 |
| 4 | lvl4.wav | 57.7s | 88 | 44 | 176 |
| 5 | lvl5.wav | 50.0s | 120 | 60 | 240 |
| 6 | lvl6.wav | 49.0s | 120 | 60 | 240 |
| 7 | lvl7.wav | 37.6s | 88 | 44 | 176 |
| 8 | lvl8.wav | 51.6s | 120 | 60 | 240 |
| 9 | lvl9.wav | 58.6s | 144 | 72 | 288 |
| 10 | lvl10.wav | 49.8s | 115 | 57 | 230 |

## Remaining Enemy Types (after removing basalt_guardian)

| Type | Pattern | Notes |
|------|---------|-------|
| ember_scout | straight | Basic enemy, medium speed |
| flare_serpent | sine | Wavy movement, rhythmic |
| swift_cinder | straight | Very fast, small, low damage |
| inferno_boss | straight | Slow, explodes into fan of spawns |

## Implementation Steps

1. [x] Fix boss spawns to inherit boss's speed (game.js)
2. [x] Update level loading for folder-based difficulty (levels.js)
3. [x] Update main.py API for folder-based structure
4. [x] Update editor for folder-based structure (editor.js, editor.html)
5. [x] Create folder structure and move existing levels to medium/
6. [x] Regenerate all 10 levels for medium difficulty (with BPM matching)
7. [x] Clone medium levels to easy/ and hard/