Some mad mixing skillz would take this song to new heights, for sure - nothing really stands out as a melody/harmony now, creating a pretty muddy track. Basically, the theme needs to come out to the front while much of the background elements need to go... well, in the background. A great arrangement can turn to crap with poor mixing, while total crap can be acceptable with great mixing, so work on it .
About the remix itself, it's pretty tight to the source in the beginning, but the shredding helps keep it distinct. I hear all sorts of video game tunage in there later - so much so you should probably warn people in the thread title that it's a medley... unless you want it to be a surprise, of course. I'm hearing various Castlevania tunes in there, Hyrule Castle (perhaps a little too obvious - it's actually a little jarring; try masking it at least a little), Megaman 1 Wily at 3:14 (the sexy, sexy beast it is), and some Tragic Prince thrown in there . Most of it meshes quite well, so good job avoiding medley-itis.
The harmony guitar seems to ring for most of the track. The textures change, but they bleed into each other so it sounds like one sound. Tighten up the performance on that, there. Don't overuse the ringing guitar texture towards the end, either - it needs to keep changing in order to keep the listener interested.
The drums... well, they need a major overhaul. That 'boom-chick' pattern is terrible, and the machine you use just takes away from the song, overall.
I love the source, and I like what you did with it, arrangement-wise, but the production indeed needs some serious tightening up, there. A re-record may fix some of the other problems I mentioned, as well. Looking forward to your next update