There are things which need improvement, but in particular the development of the flow of the story-line is something in which you seem to have put a lot of work. It was interesting to see how the antagonist dealt with each character but there are things which need to be worked on. The most important is the audio, it seems like a better sync between the voices/sound effects and music is needed, but also there was a problem where some voices seem to have had a different volume, it is important that you synchronize them in such a way that they are adjusted to each other. You could also try to look into using more esthetical backgrounds, perhaps you can ask artists on Newgrounds for help with this, it would give a different feeling to the continued episodes I think and could possibly give it a much more interesting appearance to your audience. The animation is ok, but I would suggest to reduce your tweening and try to put more time in the animation frame-by-frame, this is a difficult and time-consuming process, but regarding the good flow of the story-line you have it would really improve your animation in my opinion. The music fitted well, but for the voices and voice actors I think it is important that there is an improvement here, the voice acting could have been done better.
You are talented in the flow of the story-line and adjusting that exactly to the time lapse, but work is needed on the audio and some of the graphics.