Don't submit unfinished things or 'tests'.
It's not bad, but it's too short and it's unfinished.
The problem is that this animation is a fragment. It's a piece of what could eventually be turned into a movie, but for now, it's nothing more than a part or a bit.
The problem is not if it's bad, but rather if it's good. When it's bad, it gets a low score and gets blammed and is forgotten and gone. Done.
If it's a 'good' piece, then people get confused and may pass it. The problem is that then we've got a fragment of a piece of a bit of a flash floating around newgrounds forever, and what's the point of that? That's not what Newgrounds is about.
What's here isn't bad. But if it passes, it'll be forever unfinished, because if you complete this into a vid, you'll submit the finished item as a separate item and we'll have both finished and unfinished items floating around here, and that's not what Newgrounds is about.
It's not bad. Just, please send thru completed items. :)
As for helpful advice: Continue to practice and work on your projects, but DON'T submit things in the meantime. Just because you can submit, doesn't mean that you should. There are too many people who get all excited and impatient and decide to submit half finished or even almost finished items. Don't be like them. No one goes 'oh great! He finished it!' Rather, they go '...haven't I seen this before?' which lowers their appreciation of your work.
When you get an idea, PUT MAJOR TIME INTO IT! If you can get it done in a day, you're not done. If it takes you a week, you're probably still not done. I've seen many good ideas that passed but have horribly low scores because they got an idea, belted out a quick animation, submitted it, and now they're stuck with a low score on a crappy flash that was originally a great idea and could've been awesome, but they ruined it by rushing. Taking extra time to take it from good to great will ALWAYS pay off. Not one person who has ever had something in the top 50 got it there by submitting something that wasn't 100% finished and was EXACTLY how they wanted it to be before they submitted it. If you see things that can be made better, make them better! Work on them until they're the best they can be.