Like everyone mentioned, the camera is really annoying, it's practically impossible to aim with it unless you stand still, and as soon as you shoot, your aim is thrown off. Just anchor its origin point until you move X units and lerp whenever you cross that, it would improve it a lot.
Performance wise, I had a steady 30fps with "medium" settings. Which I find weird because the game doesn't look visually demanding.
Other than that, I somehow got stuck in the ground on the first level.