Loved this movie!!!
!!!SPOILER!!!
I will say that the first half/ beginning of this movie was very boring. As a viewer we are completely oblivious and wondering why George decides to live so isolated.
However the twist at the end bundles everything up very neatly. While watching we are engulfed in thinking that George is the one suffering with the guilt of killing his girlfriend/wife which is why the ending is so heart breaking. Also, this could be an over analysis, but the ambience is a reflection of George's emotion(s) throughout and the house signifies his brain - as it starts to malfunction.