So far I'm more interested in the plot than any other aspect of the game, specifically Rise of Lyric. Having an animal enhanced by technology and delights in that fact (and can communicate with Sonic, as opposed to say the Biolizard) butting heads with Sonic, the force of nature, could make for some really engaging dialog. The producer specifically mentioned technological enhancements as one of Lyric's traits so I really hope they come through with that.
More than anything if the plot takes itself seriously I hope the game is structured akin to SA2, where the campaign felt like a story-driven journey as opposed to a bunch of platforming stages with a silly cutscene after each one. Not bashing the Colors approach, but rather the Lost World approach. A kidnapped Tails and a forced alliance between Sonic and Eggman are concepts that could have been really interesting but ultimately felt pointless and under-utilized, respectively. Fingers crossed for Boom!