It was short, as you've stated.
Sound quality had a little echo, but was overall clear and understandable.
The character designs seemed to lack some... creativity: They're basically heads with lump-like bodies, but this seemed intentional.
You did a decent job with the lip sync.
The backgrounds were nicely done, with adequate detail. (I liked the Environmental Club poster. :P)
I'm a sucker for 'special features'. Even though there wasn't much to the movie itself, the extras make up for it.
Overall, it was short and mildly entertaining. I give it: