BATTLE ROYALE!
I love Battle Royale. :)
Anyways, about your movie... I liked the beginning (the pre-loader looked pretty good), it was well animated, but it appeared as if you were getting a little lazy with animation near the middle of the movie... The main thing I didn't like is that their heads were too fat/big. If you slimmed down their cheeks, it would look a lot more realistic.
I especially liked the beginning when it showed that year's winner; the girl looked quite frightening! But, like I said, the middle was a downer. I've never seen the movie, so I don't know what happens in it, but I have read the book, and it was different... Perhaps the book was different than the movie...
In my opinion, basing your movie off of the book, or perhaps even the manga, would have been better. I wanted to see Shogo trying to break out of the bus, and I wanted to hear Shuuya's thoughts while he saw Shogo do this. Instead, they were just placed in random places to fight.
The sound/music was pretty good. I don't think Queen was the best option for Shuuya's rock; something like "the pillows" would have been good, or even something from the Newgrounds Audio Portal (with a guitar of course). The Audio Portal would be the best option because Shuuya should play something most people can't recognize.
More voice acting would have been better. Voices can show a character's personality, and I think you could have some fun with that.
The ending was kind of abrupt, so most people that have not seen/heard of Battle Royale might not like it as much, and some people who have heard of Battle Royale might not even care for it. Perhaps when all of the characters (at least the main ones) were shown on the island, then that would have been a better place to put your "To Be Continued".
Also, there was some miss-spellings in the movie (the title, most importantly). I'm sure you can spot them if you watch the movie a few times.
Over-all, this movie was good. The animation was mostly great, but I think there should be better music, and more voice acting. Good job, you just need to improve in some areas.
I'm adding this movie to my favorites though; I love Battle Royale, and this seemed to represent it pretty well. :)
~ Kazuo_Kiriyama