Save for the Robotnik/Eggman idea (I actually prefer the name 'Eggman'), all of those are the key factors here. All of the options in the poll are the things that need to be done to save Sonic. My own option, which I feel most strongly with, is open world, simply because the games are too linear. However, the 2D option doesn't really fit with that. The original 2D games, of course, were the best (although I personally could never manage to do the up/down drums thing in the Carnival zones). The games need to be taken back to what made them great, which means 2D, unless we can introduce a non-suckish open world 3D style. Sonic Adventure was very good, and I actually liked Sonic Heroes for a time, but then got bored and sold it. Otherwise, the 3D games were the series downfall, and subsequent attempts to make it better, such as the new characters, have simply made it worse (God, I hate Charmy Bee...). Back to basics is the best policy here, if it can be done without simply a Sonic 1 rehash (i.e. different but still decent story, and some new elements that still fit with the series theme...).