I only have two tips, the later of which I don't think needs saying.
1) I think the sweeping sound (that first plays at 0:19) is either too loud or (by default) too shrill. I'd play around with it some.
2) It needs a melody of some sort.
Despite these two things, I really liked it.
Do you plan to add vocals (or something)?
edit: Oh yeah. If by bass levels you mean the volume of the bass, I think it's fine. If it was a different genre (like classical, soft rock, etc.) I'd think it's too loud, but this hip-hopish sort of music is supposed to have kind of loud bass.