3D Audio in a 2D Game?

My project:

So, as you can see, my game plays more like a 3D FPS’er that lacks in the Y/Z axis and is a sky camera view.

Now, as far as I can tell, it should simply be a matter of changing the look at of the camera systems to use the Z axis instead of the default Y(?).

Basically I’m just looking for advice or code samples before I start wasting a lot of my time.

The camera position does not need to be the same as the listener position. The listener can be at the position of the player and the sounds have their positions in the world. It doesn’t really matter that everything happens on the one plane. No need to change anything with your camera or rendering.