Fix the controls.
That's not meant to be a question, it's something that has to be done if this is to be properly called a "game". The enemies have total freedom of movement and can turn on a dime, while we wade through the four cardinal directions like we were ankle-deep in molasses, only barely able to evade or aim, and almost certainly never both at the same time. This game *could* be quite challenging, and quite diverting, but as it stands, it's merely *impossible*.