Haha what an awesome little game! I loved my time playing it! I had a ton of fun!
I spend a lot of time farming all of the ducks for their feathers and bought all of the upgrades. So when I got to the final boss I killed it in the first 1 and a half seconds!
The art is really nice! The music is really good and the sound effects are awesome they really sell that shooting sound! I also really liked the implementation of the theme! It was a really smart idea to make a shooter where you have limited bullets!
A big highlight for me was also the weapon upgrade (where you upgrade to a sniper!) I think it was really cool!
As for some critique, I think the two things that I would have suggested adding are shadows benefit the animals and player (I feel that it would make them feel a little more as "a part of the world" so to speak) and I would have also liked maybe a custom crosshair, I think it would have added a lot!
Regardless I really loved this game! You did an awesome job!