List of Needs
The rating is low not because your flash is terrible. But it is a work in progress. Things that need improvement:
--Animation: lack of fluidity in spots, looks too 2-D, the motion is way too slow, characers lacking in expressiveness.
--Sound: needs a lot more sound effects, and would benefit from some voice acting, or voice sound effects with subtitles.
--Scripting: this is the strongest point so far. Some tweaking should be done to improve clarity of the story. Keep in mind that this is a story idea that others have done, so you need to find some element, be it humor or odd plot twists, to make it unique.
--Style: I don't see a need for major changes here. Your style is yours afer all. But certainly improving the skills to draw the characters from different angles would be an improvement.