It's fun little wave based shooter. I liked the music. A couple things that could be improved are:
1. Reloading happens too quickly, I can spam R and keep shooting (infinite clip)
2. Camera does not clamp vertical rotation
3. It would be cool if when you die there was a screen that showed you your credits
4. Placing all the ui at the top left can be inconvenient to look at. Maybe credits in center top screen, health bottom left, ammo bottom right and all in a larger font.
5. When bunnies are killed, they stick around for a couple of seconds and still damage player (if it's because you want the particles to show longer, instantiate a GameObject with only the particle system when the bunny dies, or simply disable the collider)
Other than that I think this could be a solid game, great work