This is rather interesting...
Did you master this whatsoever? It doesn't sound like it, you should really start playing around with the equalizers along with compressors it'll make your music sound a lot better! That and you should tweak the volume of your individual instruments so that certain ones stand out than the others, such as the instruments playing melodies. I don't think you have the greatest library of samples either. The only thing that sounded genuinely real was the dark string ensemble but that's probably because it was a good sample on it's own, if you mastered it then it could have sounded even more amazing, along with the rest of your instruments.
Besides playing around with volume you wanna EQ your individual instruments and raise up the volume of the higher frequencies (3kHz+ (3,000+ hertz)) or make the instrument play higher notes because the entire song besides your oboe solo and your rev-crashes sounded like it was played in the 3rd octave and below, which makes the song sound kinda muddy since you have so many instruments playing in the 50Hz - 1kHz [frequency] range. If you want a real GRAND feel to your orchestrated music then you wanna hit everything between 50Hz to 20kHz! It'll give the song a more full feeling. So you should perhaps try raising your xylophone and bells an octave higher and see if it sounds better. You also could have done something to the bass trombone, it sounds really muddy because it was practically fighting for attention with the dark string ensemble since both of those instruments are playing the same very low frequencies. You need to seperate your bass trombone from your dark string ensemble, perhaps raise it an octave higher and lower the volume if you wanna keep it subtle or raise the volume of higher frequencies within it using an equalizer.
Now to your oboe solo. If you are going to put the spotlight on a specific instrument then you gotta make it SING! Make it powerful and give it some feeling! I thought the oboe needed to be louder and EQ'd a bit, also might of been cool to try out and layer it with something else. The melody it played was pretty cool, I enjoyed it =)
Now just like everyone else said, you played the rev-crash too frequently and it took a lot of attention off of everything else that it was going on since it was playing much higher frequencies.
Overall I think you could have been this song sound a lot better. It was still well composed though. (Tip: Also experiment with reeverb! I think you'll like it =])
~ Kirizzle