Before I break down my scoring, I have two icks with the track :
- I don't picture a boss theme while listening to this. In my opinion, it feels more like a first town/area theme.
- The melody is a bit too basic at times (around 01:18)
COMPOSITION WISE:
I think this is quite a creative track. I like the 5/4 time signature and the multiple key changes (e.g around 01:16), it gives a breath of fresh air to the track, which is much needed. However, like I said, this track works better as a first area theme imo. The only "boss sounding" part is around 01:59. I would picture this playing either in Zelda Wind Waker or A Hat In Time.
PRODUCTION WISE:
I think it's quite good ! The instruments have a good synergy with each other, they kind of give a silly vibe to the track (which I'm not too fond of for a boss theme, sadly).
For some reason, I really like the timpani in this track. It's present but isn't overly hearable, which I think is the perfect balance.
MIXING/MASTERING WISE :
The track sounds really busy at times. Since you went for an orchestral vibe, I would suggest you panning some instruments left and right (like the celesta/glockenspiel, I don't exactly know what you used there) and the bassoon. When the track switches to F, the flute and celesta seem to be almost TOO present, at the point where they drown the bassoon in the mix. I also feel like your cymbal hits are a bit weak, except for 01:59.
ACCURACY WISE:
I gave you the average. Like I've said, I don't actually feel like this is a boss theme apart from that one part I've mentioned. I really like this part, so I think you've racked a few more points thanks to that.
FINAL SCORE :
Composition : 8/10
Production : 6/10
Mixing/Mastering : 5/10
Accuracy : 8/15
Good job ! If only the track was a bit more serious, I would have liked it more. That was a nice track to listen to nonetheless ^^ Keep up the good work !