Honestly, I have mix feeling over the track.
In terms of rhythm, it's good, but for a boss theme, I don't think so. I can't seem to feel like my blood is pumping or the intense feeling that you're fighting a boss. The first 10 seconds do feel like a boss theme though. Overall, I don't think it's that bad, you just need to work on the track a bit more.
Still, it's a good piece of work