This is pretty good! I know how hard animation can be, seeing as I was forced into doing animation for a startup game company that, for the three years I was "working" for them, never completed a single game nor paid me for most of my time, but all the animations I did were just animated mouse cursor loops that weren't even this long and those still practically kicked the snot outta me. I'm thinking you might've used a bit TOO much motion blur (as FinaLee said earlier), but outside of that, this is smooth as silk!
Yeah, it's a loop. It's not a bad loop, but it's just that. Doesn't really matter how good three seconds of something is, it's just three seconds - with no substance it's really just a technical demo.
Some of the smoothest animation I've seen on here, man. A little heavy on the motion blur though, don't ya think?
Brilliantly smooth, this is on par with some of the old 2D animated Disney movies. I have no idea how many frames this is but you might have been able to add some quick lighting effects to make it look a little more complete. I feel like it wouldn't have been that difficult if you spent 30 hours making what you have right now.
I also agree that there's a gigantic issue with the motion blur. I don't think that it's used too much, but it's not necessary in some places. For instance, when the model kicks, her entire body blurs instead of just her leg.
Looks good you should make an animated gif.