It's not just the visual detail, it's the audio detail too. When Sonic goes past waterfalls, you hear waterfalls, when he goes into a cave, you hear cave noises.
Bwaa?
Sonic Adventure has that stuff too. In fact, some of SEGA's releases on the Genesis have these effects, that is not a big deal, especially in comparison to stuff like FarCry 2's real time plant growth.
What is a big deal is that art is unique for the first time in years and years, even if it is based off of older games. Games like Sonic Adventure 2 and Sonic Battle failed horribly in that they were basically just copy and paste jobs of the Genesis' Green Hill Zone, which I assumed I was entirely tired of (especially with how bland Splash Hill Zone was). But now with some of those great looking mountains littering the map, I know now Sonic Team was just being lazy, and they can really make old designs like this shine if they want to. It really makes me excited to imagine what we could possibly see with some of our other favorites like Ice Cap Zone.
One of the most annoying things for me in the past few "Modern Sonic" games was that all of the action was happening in the background and you were just running on bland flat platforms in front of it. With this it will probably still be a bit of an issue, but everything I saw of the Classic Sonic stuff has the most interesting bits right out front where you can actually touch them. Cool stuff.
I am surprised no one mentioned it yet, but the mountain that lifts up like an arc from the ocean near the end of Modern Sonic's gameplay video was just astounding.
