Sonic the Hedgehog 2 (1992) was the game that introduced the Super Dash Attack. The ability, referred to as Spin Dash in later games, has become one of the most beloved features of the series and, indeed, one of the most prominent features of the speedrunning scene as a whole.

In this exhilarating movie, the authors speed their way through this classic's bonus stages to collect all 7 chaos emeralds, as well as the varied acts making good use of Spin Dashes and tails to finish them in record time. They also manage to save 15.6 seconds over the previous run thanks to new routes and strategies. For more details on that, you can read their notes here.

For more Sonic the Hedgehog 2 tool-assisted speedruns, you can check out this page. It also includes runs with Knuckles, which is possible with a special cartridge lock-on combination.