Banjo-Kazooie: Grunty's Revenge is an isometric platformer released by Rare in 2003. It is an "interquel" to the original two N64 games, taking place while Gruntilda is trapped under the boulder in Spiral Mountain. Klungo creates a Mecha-Grunty suit for Grunty's soul to control, and she kidnaps Kazooie, travelling back in time 20 years (somehow) to keep Banjo and Kazooie from ever meeting! Mumbo sends Banjo back in time as well (somehow) to rescue his friend and destroy Mecha-Grunty, with the help of Bottles's ancestor, Bozzeye.

Using a trick that allows Banjo to gain insane speeds, the author is able to clip through the wall that leads to the final area, to defeat Mecha-Grunty in record time.

If you want to watch a TAS of this game that doesn't skip all the levels, you can watch the "No Levels Early" TAS here.

There is also an alternate Twitch stream featuring audio commentary by the author.