Seeing the ending, it’s pretty clear they wanted to have a trilogy. Because nothing is explained after the last scene. It’s just Faith and her sister on the rooftop. Still alive. Still on “the edge”. It’s a shame we never got a true sequel to explain what happens next.
I do have to give them credit for creating zero UI aside from one small hit-marker in the center of the screen to keep you oriented. There’s no minimap, no icon pointer, no health bar, and no ammo count for guns.