Hai!
Since you've already gotten some great feedback on the composition, I'll try and give some feedback on the mix and mastering aspects.
High to mid-endI would suggest wider stereo pan/separation on the lead flutes as they share very similar or same frequency ranges, which makes them collide a bit nasty into each other when they play in unison. A different solution would be changing one of the flutes to a different type, perhaps an alto, or playing the other flute at a different octave (if possible).
Low-endI feel the bass line instrument collides with the bassy drum in the lower end, causing it to be a bit unclear and distracting. Perhaps dodge the bass line's freqs from the drum and cut the subsonic freqs from the drum as well.
The vibraphone-type instrument could also get some of its mid/low bass freqs reduced a bit to further clean up the mid/low-end.
These are just my suggestions on how to improve the presentation of the composition from my point of view.
Overall I think it sounds great for someone who is a bit novice with music production, not bad at all. Keep it up!
I currently don't have my studio monitors setup and only took a few listen's through reference my cans.
Have a MAD day!