not bad for your first time.
I have to agree with a few things about what Infamous Borlaug has said about the things in this flash. But this being your first time and especially your first flash, it is very impressive. It seems like you took a lot of work to make all of it becuase, I can see you took the time to make it quite detailed.
But there was something in there that lacked....I can't place my finger on it. I beleive its the fact that it doesnt give the viewer a feeling of "excitement" (or at least it doesnt give me that feeling of excitement that much). Maybe its the music that was being played or maybe its the fact that I don't know about Megaman Zero that well (Im an old schooler when it comes to megaman...I played the earlier games.)
But None the less, I encourage you to continue making flashes. I can see you are already good at it, and you will become even better with time. Good luck on all of your future flashes, its a very impressive beginning for you, my friend.