I think you should re-think this!
I really dont think a Sonic rpg using sprits from the old sonic games for the mega-drive is such a good idea. The whole point of a sonic game is to be fast paced and quick. The slow RPG style dosn't suit sonic. even more the animation is jerky and slow and the dialoge is very weak. If you really want to make an sonic RPG that bad try and use better animation.