The things that make Sonic a great game are speed and the loops IMHO. Those things won't be able with Backbone or Amos. Without those I'm afraid this project won't be anything more than nice try but no sigar.
Maybe if we could get a programmer on this project this would be something that could be cool though. Maybe the programmer that works on Mr. Beanbag, Tricky, can be involved? She mentioned turning her engine into a game creator app not too long ago.
