Not bad, for a first try.
As someone who tried - and failed - to submit a successful flash to the portal a few years ago, I can sympathise with anyone trying to make one for the portal. For the flash itself, you need to use more frames per second to make animations smoother, and the character animations themselves still need work. But that's the kind of thing that comes with time, and for a first flash this is still really good - it's the "story" behind the flash that helps it shine, I think. Good luck with future flashes!