Not a bad flash. The animation and rigging are stellar, and the voicework is top-notch as well. It is a little short for my preference, but that's the way it goes with this sort of animation, and the animation that's there makes up for the brief length.
Unfortunately, the joke of the flash came a little too far out of left field for me. I think that maybe the buildup (hah, buildup) of the joke didn't provide enough of a clue or possibly the payoff was too sudden, or possibly both. I didn't really understand the joke as it happened, and by the time I connected the dots, the moment had passed. It's a big shame, but comedy is a cruel mistress. Thankfully, the repeat of the joke after the credits partially salvaged the humor, since by then I was up to speed.
In short, it's great animation with a joke that didn't quite work. You don't get full marks, but you get points for very nearly getting it right.