This was actually quite fun! I can see where the others are coming from re: camera, but once i got used to it and took my time it worked quite well :) the idea behind this is great, and i love how the bullets curve around the donut as well. Plus the effects look great!
I reckon the camera isn't as much an issue as the size of the donut is - if it was a bit bigger, there would be a slower transition and less drastic/sharp curves that may be throwing folks off. That would also help with keeping track of where thing are, and lining up to the glowy orbs that act as your ammo too. But the core idea and elements all work, it's just fine-tuning those details!
Overall this was definitely a fun little game, and i can see this being developed further into a super neat little arcade game!