A great work of art, but lacking in voice acting.
As animation goes, this is incredibly good. It's fluid, the soundtrack for it involves the characters and plot quite nicely, and the storyline, while certainly not the most original, is compelling enough for the viewers to follow.
The major flaw in this, however, is that you're attempting to do the voice-acting all on your own. I felt deprived from the characters' own individual traits in your taking on the entire cast for yourself. In the future, try to recruit others to do the voiceovers for you. There are many that would jump at a chance to do such work, for free as well. Stick to your strengths as an animator, and let others fill in the blanks.