The 4-5-6 idea is quite original - I haven't seen anyone come up with that division. There's a bit of an unsteady beginning; I'd suggest going with the two-note sequence first (rather than begin on one note). I began with the impression that it was going to be the same throughout - yes, they were the same chords throughout, but you built up the piece quite well.
The filmgrain at the back is really nice and adds to the atmosphere. The piece has a good climax and a good end. And when it does get louder, there is some underlying tension, as if someone were to walk out and do some things hurriedly on a rainy night.
If this were YouTube, I'd like this. I guess that should be enough to say it's a good piece.