This is a tool-assisted speedrun. For more information, see http://tasvideos.org/3414M.html. TAS originally published on 2017-06-04.
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.
While this movie appears to be around 3 seconds slower than the previous movie (http://tasvideos.org/1665M.html), it is in fact faster. This is due to more accurate emulation and also including the GBA boot sequence.