The intro is so cool, Iike the melody. The buildup could use some more energy. try to add a thick snare with the kick drum and automat the pitch to go up. The growls are very classic sounding, try to sprinkle them with a little stereo imaging and distortion. also add a wide reverb with a short decay to your snare.
The beat change at the second drop is very nice, its feels like drum and bass. It was awesome when brought back the melody over the drop. I love how it sounds. One more thing, you must sidechain your growls to your kick to give more punch