Nostalgic...
Back when I dabbled in Flash animation, I always remembered that one of the most important and difficult things to animate well was the walk cycle.
For that reason, I give you a 9, on top of the fact that there's a high amount of style here, and your characters are all well-drawn, creative, and interesting to watch.
Had you turned this into some kind of full narrative story, I probably would have given you a 10.