It's pretty clear what you based this on, but it works well, so good job! I really like the idea of having to shoot the bunnies off of invincible drones. Two things I noticed:
- Your drone NavAgents are still displaying their paths to the player (debug)
- When holding one weapon and picking up ammo for the other, the ammo counter will display ammo for the wrong weapon. I didn't check to see if firing would fix it because I just switched weapons each time, and that worked fine =)