I too love Serum, FL, and Virtual Riot xD
This is really good! The harmonies are interesting but don't sound bad.
I have only a few criticisms:
1. Sample choice and diversity. For much of the piece, the snare is the same, and it needs a higher pitch IMO.
2.The dubstep is really good, but extremely repetitive.
3.The harmonies OCCASIONALLY cross in ways that don't mix.