I had some unreasonably high expectations going into this song so I can't say this is one of my favorites, but I was certainly not disappointed in the least. I think you captured the feel of the game pretty perfectly. I wasn't to0 enthusiastic about the beginning "YOU DIED" section because it just seemed a bit too funny to me compared to the rest of the song. BUT, it definitely fits with the how the game is, so I can't call that a fault.
Another thought, as much as I like Dark Souls as a whole(which is a lot), I think it's a shame that pretty much all the focus is on its difficulty when the story is actually fairly deep and interesting, if a bit too minimalist and purposely ambiguous.