I feel like not being able to control where you aim is a good concept but it makes the game feel unresponsive and almost clunky. I'd recommend making it so that you can still control aim but in a weird way. Something that hurts you to aim such as having to move away. Make aiming sudo controllable.
Also, the pacing feels very slow. Maybe if there were more enemies on the screen or even different kinds of enemies it would feel a lot more lively.