Points added, guns now properly look at the mouse, and PARTICLES
http://dl.dropbox.com/u/96086/ld25/ld25_v_0.0.html
I can never get particles to not look junky 
Via this handy little script I sort of figured out:
#pragma strict
function Update () {
var gunPlane : Plane = new Plane(Vector3.up, transform.position);
var hitdist : float = 0.0;
var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if(gunPlane.Raycast(ray, hitdist))
{
var targetPosition : Vector3 = ray.GetPoint(hitdist);
transform.LookAt(targetPosition);
}
}
