Ludicrous-speed bouncing around. Completed without collecting any emeralds, with both Sonic and Tails controlled by the player.
This run takes everything you know about Sonic 3 & Knuckles and turns it upside-down. It extensively uses the "scroll objects offscreen to pass through them" trick to zip and warp to places that shouldn't be reached, break bosses, and effectively skip entire stages.
It is worth noting that nitsuja and Upthorn did not directly participate in the creation of this movie; instead, marzojr incorporated several additional tricks in multiple stages and spliced them in for a total improvement of 02:14.32 seconds over his last effort at doing the same.
The second YouTube link is to the camhacked HD encode, which attempts to always keep Sonic onscreen and puts HD sprites on top of the background to make the TAS look even better. Camhacked SD downloadables are also available in the Archive collection.