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 and 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 did not directly participate in the creation of this movie; instead, upthorn incorporated newly discovered tricks in several stages and spliced them in for a total improvement of 49 seconds.
The encodes in the second set use a camhack, which attempts to always keep the characters onscreen and puts HD sprites on top of the background to make the TAS look even better.