I agree with the guy below me.
This is one of the most overdone ideas here. But, it is your flash, not mine.
Now, the improvements...
1. The running seemed to be a little slow. Mario didn't move as fast as he should have. The whole fight was a little slow paced, but it got the job done.
2. The music didn't seem to fit. I sense some inspiration from the Power Star series. The song, the sprites, the fight. It seemed like you tried to do it in the same style.
Anyway, everything seemed to go smoothly, except for when it went from the fight suddenly stopping to about halfway through the credits. I have no clue what caused that... and I don't even pretend to know... Anyway, I hope this helps you out. Bad English? You speak English better than some people I know. And English is their FIRST language. But, if you need help with text or possible sentence structure in future flashes, I would be happy to help.