Added:
- **12 trees** with brown trunks and green foliage scattered throughout the map
- **5 buildings** with random sizes and lit windows for an urban atmosphere
- **More crates** (increased from 10 to 15)
- **More zombies** - starting wave now has 8 zombies (up from 5), and each wave adds 5 more (up from 3)

**Next Ideas:**
1. **Explosive Barrels** - Add red barrels that explode on impact, causing splash damage to nearby zombies
2. **Weapon Variety** - Add a shotgun, sniper rifle, or SMG with different damage/fire rates that you can switch between

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