I really loved it overall. I'd love to perform this. Your harmonies are great. Strict tonality is something I've always tried to get away from. You have a great grasp of extended and dissonant tonalities. Your orchestration is relatively fresh and interesting.
A few specific comments:
There's a really nasty 2nd or something in the bass at about 35s. It's usually inadvisable to have anything closer than a 4th that low. But then again, this is a "nasty" sort of piece.
In a lot of parts it's either straight eighth-note counterpoint or static whole notes in the accompaniment. It might be nice to create leading tones and short suspensions and the like. General rhythmic variety would help too.
I like the brass part at 6m. And right at 10m.
Some of your notes seem really long. I suppose that could be worked out in sections, but it'd still be pretty tiring...
Great piece over all though.