I like the dark, apprehensive mood. It has a good sense of climax for the first 30 seconds or so, but then you appeared to switch gears to this busy, rhythmic section at :32. By then, I would've liked to see more melodic content seeping into the piece. I also think you overused the pulsing mid-range bass at :41. Once it comes in 3 seconds apart (:41 and :44), I think you've gone too far. I think if you had some stronger melodies here, it would help give this piece more shape. Right now it seems like it's oscillating between faster and slower-paced sections, but overall it doesn't have much of a sense of direction. Repetitive riffs usually don't make good melodies, and this is no exception. Perhaps you'd find this news post helpful: http://johnfn.newgrounds.com/news/post/937050. Also, I think you had a few too many higher frequencies in there. I would've put more effort into making sure the frequencies in the bass and kick don't overlap. That way, you can make the kick sound clear without having to add any treble tones. Some compression also couldn't hurt. It was a smooth loop, though, and I liked your instruments, even if they were a bit generic. I bombarded you with a lot of different things to work on, but I'd suggest working on them one or two at a time for maximal improvement. Maybe you could focus on writing some memorable melodies for next time, and then start to work on your mixing skills? I'm no expert, but I'm always willing to help. Feel free to PM me again when you have a new track! ^^