I actually like it a lot. It works perfect for what it is meant to be, an adventure/boss track
I don't think there's need for too much melody variation.
I understand what you mean by making the sub woofer shake and all that, but you don't need to peak your volumes to do it, there are many ways to do that effect but they require a lot of practice, I still can't get it right haha
I really like it, I can imagine it in a video game.