Here's what I added:

**Boss Fight (both levels):**
- A boss arena near the end of each level with gate walls that lock you in
- **Level 1: Dark Dragon** (15 HP, shoots projectiles, phase 2 at half health with spread shots)
- **Level 2: Sand Wyrm** (20 HP, tougher, faster attacks)
- Boss has a health bar, screen shake, roar SFX, and a dramatic defeat animation
- The jewel only appears after defeating the boss

**Level 2 - The Desert:**
- After beating Level 1, the victory screen shows "NEXT: THE DESERT →"
- Desert character select with 3 new themed heroes:
  - **Samurai** (4 HP) - SLASH WAVE: ranged sword energy attack
  - **Desert Druid** (5 HP) - VINE WHIP: piercing long-range lash + passive heal every 5s
  - **Sun Paladin** (6 HP) - HOLY BOLT: piercing high-damage light projectile
- Desert level features sand-colored platforms, desert background, and desert enemies (mummies, scorpions)
- Each character has unique generated names (Ronin Musashi, Ancient Thornwalker, Holy Solarius, etc.)

**Next Ideas:**
1. **Level 3 - Ice Caverns** - Add a frozen level with ice physics (slippery platforms), blizzard enemies, and 3 new frost-themed heroes
2. **Boss Patterns** - Give bosses more attack phases like ground slams, minion spawns, and telegraphed area attacks

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