This movie of Sonic Advance is unique as a speedrun in one aspect: Sonic moves so fast that the "camera" of the game cannot even follow him. Therefore, he is rarely seen in the movie.
On the rare occasions we get to watch Sonic, we get to enjoy seeing him moving through walls, charging up for another dash, or making short work of bosses.
Besides the super fast speed itself, the speed also provides Sonic an ability (glitch) to pass through platforms and walls under certain conditions.
Mukki's TAS improves the previous run by 00:30.95 seconds, thanks to new routes and glitches explained in his comments.
Watch this run being played back on a real console.
Note: There are two encodes available for download; the first one is the original version, and the second one is a comparison encode: you can see the original version to the left, and what you see to the right is something made with a special emulator, hacked to force the game's camera to focus on Sonic, making it much easier to follow what Mukki is doing with him. The second YouTube stream displays these views side-by-side as well.