I thought the drums sounded "heavy" enough. To me, they don't sound as upfront as they can because the guitars are crowding them out. To me, the mix sounds like everything (drums, guits, vocal) are all trying to be the main attraction. So they step on each other.
If you want the drums to stand out more, you could turn down the guitars.
The vocal level could be improved by a couple of things I think. Use a volume envelope in your DAW. Also give it an EQ boost somewhere between 4500hz and 6000hz.
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Oh and I liked the song and performance.