rawr!
Not bad at all sir. I actually didn't know you could do dnb at all. Really good job for someone whose new to the genre.
When things kick in, it sounds like something is clipping. Clipping happens when you over amplify the signal and it's basically just a tad bit of digital distortion that never sounds good. I'd recommend turning down whatever is causing it, or try slapping on a compressor.
Nosebleed was right about the rhythm, but I think he could have given you better advice. One thing I really like doing with my hi-hats is to set up my rhythm with two of them. I put a little bit of delay on one of them, then I use the other hat to accent the rhythm the delay creates. It's kind of a weird idea to follow, but if you experiment with it, you can get some interesting rhythms.
I don't know if you do this, but layering your drums can also help out. It takes some experimentation, but it's such a fun technique. Again, I'm not sure if you do that, but it can really fatten up the kit for a nice full sound if it's done right. Beautiful snare btw.
One more really cool thing to do with the kit is to change up the velocities of the notes. Doing this creates a really dynamic rhythm. I guess an example of what this means would be to have a really powerful kick followed up with a slightly weaker kick. It makes everything seem a little more organic. You can also do this if your layering those drums by having only one kick play at a given time, and syncopate it to accent notes.
It's all subjective, but I got a lot of this advice from people I consider much better than myself. If you don't like it, hate on Rig.