This song sounds......... flat. You're probably using defaults, as am I, but you have not learnt the ever so beautiful technique of EQ. Originally I thought this was a hip-hop song. And the sad thing is, I know what you're intending to get with this song. Without the EQ, where you isolate certain frequencies and bring them out, the entire song becomes a flat, muddy mess.

And since when did techno songs have dubstep wubs? Shouldn't this have been put under dubstep in the end? You may want to drop the other instruments, or EQ them well, for this section.

Notice that I said the word "EQ" A LOT. Good mixing can go a long way. I would go into the how and why, but it'd be impossible to do so especially when I have pictorial examples. If ever you need help, PM me or even just post a thread in the audio forum about it; there will be at least a few people willing to help.

This isn't really my genre of music (I'm a cinematic composer), but I think this could be a bit better.
1) I'd try making sure the bass notes are the roots of the chords- this would clash less with the chords because the bass had a lot of overtones.
2) If I were you, I'd experiment with chords a bit. Especially since the chord progression repeats so much, changing one or two chords could make for an interesting moment. I'd also try using a bit of dissonance, such as 7th chords and stuff, occasionally. Nice song, actually!

Not bad, maybe pump up the drums a little