This could turn out great with some changes.......
I might go on about this for a long time, so forgive me if I do. This is just constructive criticism, nothing negative here.
First off, if you are not sure about coding, you should either choose Sonic or Shadow for the main character. This would cut your time by more than half. Second, the personality of the characters. Shadow seems to excited about the whole battle cards thing. I'm not saying he shouldn't use cards, but he shouldn't be so hyper about it. Also, the battle cards shouldn't be talked about in the story like Sonic did, but rather something that only comes up during the battle. I just can't see Shadow showing much interest in cards. Next would be the cut scenes. I do not think showing an island instead of the speaking characters will help the game. Also the scenes should not show more background scenery than the characters. That is why most sprite movies and sometimes games fail. Next thing, music. Try to use music that is not overused so much (EX. Final Fantasy 7). I think you should stick with the Sonic 2006 Music. Next is the battle scenes. By the looks of it so far, its good at first but it may not last long. Hopefully that concept will change. Now the animation. It's great but I believe it could by superior by bumping up the Frame Per Second (FPS) rate. Also, hand making the action animation (EX. Gerald Gun) will increase the dramatic effect. If you are not sure also, ask some people for help with your grammar. Lastly, you need a save feature, all I can say is google it or go on flash kit. Other than that I wish you good luck on this game. I know a good movie or game takes 6 months but you might want to spend more time on it. Also do not stuff the entire story into one flash. It will allow more people to beg you to make the next one, lol. Oh yeah, this review is long because I am a big fan of Sonic and Shadow (despite some lousy game releases). Great demo, great idea, keep me surprised with your next release.