This... was probably not the type of thing they wanted IGN to see:
http://www.tssznews.com/2011/06/10/e3-video-city-escape-breaks-during-live-ign-demo/
What's weird is, as pointed out in the comments,
that section doesn't even have speed boosters in the trailer, which means they were either pulled out or made invisible just for the trailer, or they were stuck in to try to force the section to work when it had problems, which is a bad habit they've had for the 3D games for a while now.
Kard8p3 said:
Don't know if it's been posted but here's footage of the 3DS version
Classic sonic
http://www.youtube.com/watch?v=cIau-_VQWy4
Modern sonic
http://www.youtube.com/watch?v=rU3oFpF1Vt0
So in that 1 minute Classic Sonic video we have:
-Heavily-Recycled "current" sound effects (including the annoying wasp noise from Unleashed, especially the Wii version)
-Uncurling for no legitimate reason
-Obvious glitches (Sonic's rings fall through the bridge instead of bouncing off of it, bogging down framerate)
-A very short zone (technically the Genesis stages weren't that long either, but this wasn't exactly a speedrun) with a very awkward ending
I like how Modern Sonic's almost like he's "cheating" his way through a 2D stage instead of legitimately 3D level, zipping on rails around the sections instead of following it linearly. But that's looking pretty poor so far. And the physics have to be consisted with the 360/PS3 version, there's little reason for them not to be.