Hi Jim,
My backgrounds from an overall arrangement POV, hope it'll be useful!
At first I thought it was a bit busy, but there's great sections where it pulls back to just drums, bass, synth lines, great build up between sections, it could be improved by pulling back eeeven more? A well placed silence would be epic in this, before a blast. Sort of like the boss has just burst in.
Though the loop is a good starting point, you could try to have two distinct chord structures/riffs to go over the same underlying bass line? Then structure like A-B-C-B-A or something.
Overall I really liked it, really tense which is the best thing for a boss battle!

Hi there! :) I review/criticize tracks on the audio portal in three categories:
- Mixing (Technical part, volume, frequency balance, etc.)
- Composition (Melody, chord progression, intervals, etc.)
- Feeling (Basically what I feel while listening)
Remember, this is all my personal opinion ;) I listen with a Sennheiser 650 HD headphone.
I apologize in advanced for my English :D

Mixing:
Overall nicely done :) The synths are mixed quite well together. You can hear every sound and melody line. The stereo image is nice, it balances out the track. The only thing I can mention is the beat. In my opinion, the sound of the snare doesn’t punch through the bassline / other sounds of the track. That is really a shame, because it would give the track even more power! Try to gain it up and boost around 150-180 Hz.

Composition:
AWSOME. It’s weird, it’s creepy and very big. Even when you hear 3 melody lines together, everything fits. I’m impressed :)

Feeling:
I assume it boss fight music because of the title. This gives me the feeling of a boss fight ^^ To me it gives the feeling of „danger is coming!”, because it’s kind of creepy and aggressive music. I can totally see this in a video game ;) The only thing that bothers me that it cuts of at the end, I look forward to the full version of this track ^^

Overal opinion: Awsome track ^^
Rating: 4 stars