Hi,
I like the general feel of your work, it is kinda dark which is something i always like and it feels like something pretty bad happened. So, i think you get the ambient part right.
But it is kinda hard to review on it because it's basically the same stuff with variations in the background during the whole piece. So i can't say much except that i like what you did but there is definitly a need to thing about a movie or something to go with it like you said, else it might be better to have some kind of second main theme.