Wonderful.
Its not that dark really.
The strings do add a flavour of darkness, but I would put all my darkness bet on the bass you have going on there. It is the pillar that holds everything together, which makes it sound quite dark.
And that scribbling noise... *shivers* that scared the crap out of me.
That guitar noise you have going has too much delay and resonates too much, it overlaps each note too much, and becomes a bit too messy. I suggest either cropping it, remove delay/resonance, or find another instrument. I would recommend maybe a synth saw, I feel it would also aid the dark qualities in this piece.
Still it was a great piece.
5/5 from me, keep them coming.