They are quite big and can obscure some of the other assets. The unfilled bar and the border make them very present and distracting as well. I would suggest dropping the bars entirely and use some tinting mechanic on the actual enemy sprites or something more subtle like numbers. The rotation of the healthbars makes the game look more dynamic, but they are more distracting than helpful. Think about what info the player really needs. Is the rotation helping the player see the enemy health better or is it helping in any other way?