The Official Newgrounds Welcoming Party.
Well first off, this may be a bit repetitve, but welcome to Newgrounds. To be truthful, this isn't half bad compared to most people that post flash here. It's definetly better than Fred's material. If you're interested mainly in Sprite animations than you might want to think about these tips. They may have been said already, but since I'm saying it now, it's definetly the truth.
1. Where is the Sound?- I just got back from reviewing JohnnyUtah's silent film of Transformers and his was in the old school silent film fashion. If you gonna add no sound, you might as well do that. Without audio, most creations are pretty much boring and emotionless.
2. Kick It Up A Notch- No I don't mean add some spice into it like Emril. I mean speed the animation up. This is like looking at the Matrix slo-mo, but throughout the whole movie. Now I'm not saying to make it as fast as Sonic, but enough frames per minute to make it more action-filled.
3. Enter Flash In Style- Sometimes it's better to keep the audience waiting with a preloader. People like to be distracted by little things like drawings and the little tank in the center. You'll be fullfilling their fantasy if you install a preloader game to entertain them. Preloaders also will let the audience know when your movie ends. There are some stupid people in the world that will actually continue looking at your repeated flash, wondering when it's ever going to end. So preloaders not only entertain and maintain hype, they also prevent riots out of stupidity.
For more tips on how to make a good flash, I suggest viewing the "How to be an Animator God" series. It's thenup to you to follow it's...advice and rise from dud to stardom.