| John:
I like the vibe you are going for. Since it's a demo, no point commenting to much on the mix, but there are few musical comments.
1. The synth work at the beginning of the song seems superfluous unless you are going to incorporate the synth into the rest of the song. (Which might be a serious possibility.) If you plan to incorporate the synth, I'd programme a patch with a little more grid to it. The smooth portamento synth stuff just isn't blending with the rest of the vibe.
2. Melodyne the vocals. Auto-tune isn't for everyone, but you're at the point where the music isn't as good as it could be because the tuning is out. No worries. Just adjust it a little bit. Keep the character of some of the out-of-tune notes, but reign the tuning in a bit so that the whole vocals don't sound consistently off. Your voice has got a lot of character and gruff; I think good tuning would just go to direct the listener to the real character of how you sound.
3. Change the drum beat for the first few choruses, to accentuate the difference in sections.
Hope this was helpful. I'd be happy to give you more advice, too, if you find this helpful. My own stuff is in a pretty different genre (electropop), but so many of the problems in composition and recording are shared across genres. | 
