The `index.html` was missing — that's what caused the 404. I've built the full Arsenal FPS game with:

- First-person movement (WASD), mouse aiming with pointer lock, jumping (Space)
- Weapon model loaded from `weapon.glb`, with recoil and muzzle flash
- Enemy robots loaded from `enemy.glb` that chase you and shoot back
- Health system, ammo with reload (R), score tracking
- Procedural audio (Web Audio API) for gunshots, hit markers, kills, damage
- Neon-accented arena with cover objects, pillars, and grid floor
- Wave-based spawning with increasing difficulty
- Playscape SDK integration with mobile dual-stick controls

**Next Ideas:**
1. **Weapon Variety** - Add a shotgun and sniper rifle with different fire rates, damage, and spread patterns, switchable with number keys
2. **Enemy Types** - Add a fast melee rusher and a slow heavy-armored enemy with different attack patterns

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