Great story.
The graphics were awesome, though the animation less so. When they were running, it looked a bit shit, as if you were tweening each leg as a whole. In other instances, overly limited frames looked choppy.
Also, the sound seemed out of synch on occasion.
The plot and pacing were incredible with a beginning to capture the interest quickly and various unexpected turns and a nice revealing of the overall plot.
I'm really excited to see this begin properly.
If the final series is as intelligent as the intro, it could be one of my favourite stories on NG.
Just a bit of a shame about your animation. Either animate the legs properly, each joint seperately, or try to not show the legs.