The mix is very messy, so really work on levelling everything appropriately. For example, hats are too loud and some FX is too loud. Because of things like that, it sounds very cluttered overall.
There is too much reverb as well. Watch out for that. I know reverb is very tempting because echoes sound cool, but for a good mix you need to minimize the amount of reverb you use to little or none.
The build up is kind of boring. Try to recreate different styles of buildups with pitch automations, EQ automations, etc (But similarly to the use of reverb, don't use too much).
This sounds like you are not to familiar with dubstep yet, but with time you can improve.
When you have more experience with mixing and sound design, try to recreate this. It might sound amazing if you try again at some point.
Good luck.