The guitars are FAR too boomy. Slap whoever mixed this for you, because they should have clamped down on the bass frequencies on the guitar. That would have helped a lot, and should have gone without saying.

The cymbals could use with some more compression - not a lot, just use a multi-band compressor to clamp down on those highs by say...3 dB? They just sound a bit too 'all over the place', if you ask me. If I could, I'd try out it, since I'd be interested in trying a few things, but I can't. Oh well. It's like the cymbals are sitting on top of everything else, instead of simply being in the background.

Boost the mids on your vocals. Your voice is simply not cutting through enough. Actually, scratch that. It cuts through fine - it just sounds like its not cutting through because of the tons of bass/boom on the guitars.

Wheres the effing bass guitar? Were you trying to cover up for it by leaving in all the bass frequencies on the guitars? Please don't do that. =/
Wait. your myspace says theres a bass player...Where is he on the track, or am I somehow deaf?

See, I checked to see if maybe it was just my speakers on this PC that wasn't showing any bass, but I played your song back through the monitors in my music room, and I still can't hear it.

Boost the highs on the double kick a bit, if you want it to cut through.

Finally; I know you'll hate me for saying this, but please rewrite that song. It doesn't feel like it has any coherent structure that the listener can grasp onto or make the song memorable for them (okay, just me). I'm guessing you guys didn't have a producer (or the producer was/is a noob), because I, personally, would have hammered you about it.

But it's just a demo; it can be fixed.