This is a very eerie and well written track with a lot of potential.
Composition wise, it has some really interesting components. To me it sounds like a horror theme from the more difficult level of a RPG with the development behind its repeating melody. All parts seem to suit this well, from the first sections brash staccato strings and eerie celeste*, to the second sections overpowering percussion and manic synth lines, these elements definitely add tension and maintain a high until the end.
But, while at the base you have the components of an eerie track, I believe there are some subtleties that are missed through the mix (which also contribute on the composition side of things) that would keep it from sounding more professional. It seems as though you've decided to add elements solely on 4 bar repeats which to me isn't building an gradual ramped and uncertain atmosphere, as it is stacking blocks on top of each other until it gets to its peak. In the introduction it would be especially effective if you were to have subtle instruments and atmospheres creeping in and out, this would leave me as the listener uncertain of where its going, which is definitely what you want if you're trying to make people pee their pants.
I'm sorry if I've been a bit cruel there. What I'm pointing out is definitely something I struggle with as well as its one of the hardest things to tackle when producing a track, but if you manage to add the right subtleties into places that would build the track in a way that the average listener would not consciously realise, then you can make the repetitive elements constantly develop in unexpected ways and really hold a persons. I think there's nothing wrong with the instruments you've used here, its just the atmosphere behind them I think is missing and thats definitely something that can be added in and developed if you want to do that
Great job anyway, man! I did enjoy this track. :)
*correct me if this isn't a celeste, I'm not sure here