It’s technically not a “complete” run, as a section of Classic Sonic’s section is missing, but you get to see all of Green Hill here in this video, uninterrupted by Takashi Iizuka, Honorary Conquistador. You can hear the in-game audio, soundtrack… everything.
That part where Classic Sonic is in the cave and the bird sound effects kick in… that’s a real nice touch. Total zen moment. On the other side of things, you get to see the redundancy of boosting on boost pads and grind rails. Tons and tons of grind rails.