Lack of gameplay consideration
It's disappointing that so much apparent effort was made to make this game look good, and how bad it turned out.
It actually seems that you took steps to make the game more frustrating. If you ever had the thought "Wouldn't it be cool if the camera shifts the view erratically as the player tries to move?" the answer is no. No because what you have done makes the game unplayable without getting motion sickness. You can either take out the camera spasms entirely, or you can try to make it more manageable like in Super Smash Bros, but you can't leave it as is now.