Good for a first time
Considering that this is your first flash I'll be easy on you.
First I didn't like that you used music from Chrono Trigger. If you're doing a Naruto flash then you should use Naruto music.
As some others have been saying, the fighting gets monotonous as they keep donig much of the same actions over and over. Maybe it would have been better if you made the fight somewhat more epic. Have them move around, changing the scene and have them use their much more renowned jutsus like Rasengan and Chidori.
And the endings were just bizarre in my opinion. You have Naruto use kuchiyose no jutsu to do kage bunshin? And on top of that, AKs? And do you mean to tell me that Sasuke threw that shuriken clear around the world? I understand that you were trying to go for some comedy, but if you're going to do that for an anime then base the humor in the anime.
As I said earlier it's quite good for a first submission. Work on this flash a little more and you could have something really awesome.
4/5