Perfect! I've successfully expanded "Hollow Depths" with 5 additional levels. Here's what was added:

**Level Summary:**
1. **Level 1** (Original) - Tutorial area with basic enemies
2. **Level 2: Crystal Caverns** - More platforms, increased enemy count
3. **Level 3: Abyssal Depths** - Narrower platforms, more aerial enemies, stronger Heavy Husks
4. **Level 4: The Hollow Core** - Harder enemies with more health, complex platforming
5. **Level 5: Forgotten Sanctuary** - Final challenge with toughest enemies
6. **Level 6** - Victory area at the end portal

**What Changed:**
- World expanded from 3,200 to 16,000 pixels wide
- Added 80+ new platforms across all levels
- Added 50+ new enemies with increasing difficulty (stronger health, better detection)
- Added 40+ new collectibles with higher geo values in later levels
- Added 18 new checkpoints (healing stations)
- Level indicator in HUD showing current level (1-6)
- Visual level transition markers with names appearing on-screen
- Progressive difficulty: enemies get more health and better stats in later levels

**Next Ideas:**
1. **Boss Battles** - Add unique boss enemies at the end of each level with special attack patterns and phases
2. **Power-Up System** - Collect permanent upgrades like double jump, longer dash, stronger attacks, or health increases throughout the levels

**Ready to level up your game? Pick one and let's build it!**