Because the stuff you've done is good I'm going to be picky in the hopes of helping you get even better. Do you mind? I have the best intentions at heart.
When you write classical music with midi you have to try and emulate real playing as much as possible. Something you'd never hear in real live performances is heavy silences between notes such as the gaps between each note played by the cello/double bass (low instruments) in A Perfect Moon.
To fix this all you have to do is make the midi notes cross over a bit so one sample starts just before another ends.
Next, on the composition side, it's all nice and pretty but everything seems to be playing the same thing the piano played, the same chords, the same melodies.
You could try writing a 2nd complimentary melody for the oboe that comes in 1/2 way through to really make this piece something special.
In Isaiah's last stand I found the rough synth quite jarring (although this is most likely due to personal taste and you can disregard this) so I would have cut out some of the higher frequencies to make it a bit smoother.
The bass is sweet btw.
I hope this helps - once again, I'm being picky because you have the basics down already and just saying "good job!" wouldn't benefit you at all.
