None of the buttons work, except for "Scenes" and "Main Menu", I had to right click and hit play to even view the animation. Some of the animation was either too slow or didn't show any fluidity, while the camera was also too zoomed in to the characters while he was attacking. FLOATING LETTER, you could've found some poses to work around that like he actually went to the letter. Sonics' dash off the steps was unnecessary, a jump would've worked better. Saw the boundaries for the black box fading in, and for one of the skies. Multitude of sound clips for characters playing out of nowhere and unfitting music playing for the scenes and the sudden end.
I know you lost the .fla, but uploading something like this (especially with it barely functioning) is not good. If you lost the .fla then begin remaking it, you're not obligated to upload this.
Overall, I wouldn't give this a good rating but some of this animation is not that bad if you'll continue! If you need someone to preview, test and help you with the flash I'm open to help! If you have skype, my contact is on my Newgrounds or message me on Newgrounds.