Well... as you may know, I have the files of sonic world, and I played a bit with them, i replaced Mecha Sonic with Enerjak, and made my concept of a Final Boss for this game. It is a pretty hard boss battle, but a really fun one. As in the stage Storm Station, if you touch the red circles, you die.
I can't upload a link for this for obvious reasons, but let me know what you think.