Alot you can improve
Hmm... I don't know where to start exactly.
I didn't feel any kind of good context, try picking a story or something like...
- Introduction - Normal day - Problem Emerges - Attempt to solve - Solved
Audio handling and picking out a track that works with your animation and if the animation gets longer than the sound track, it would be fitting to choose a track that both works with the animation and is loop friendly.
Remember, sometimes quality doesn't have to mean popularity. Even stick figures can make it to the frontpage if they've got a funny point or reach out to the right audience, though I suppose they'd have to be flowing also in the animation itself, not looking different from time to time or you can't see what they do. But ofcourse, as an artist you'd want to constantly improve your graphics materials, getting more advanced, though it takes time and practice.
Adding voices is usually a good way to create a good atmosphere, if you have voice actors or you're voice acting yourself while having fun pitching it and such.
I hope this review was useful to you ^_^