Shovel Knight received various platform-specific sidequests and special gear, including God of War / Kratos-related stuff for PlayStation devices, as well as Battletoads-related stuff for Xbox One.
Now, the Battletoads content for the game has been released for the PC version, as well as the Shovel Knight: Treasure Trove version.
The Battletoads fight is found in the Hall of Champions, where three of the toads: Rash, Zitz, and Pimple appear. You’ll get a new level to progress through, a new boss to battle, and new Toad Gear armor to obtain after completing everything.
Shovel Knight is currently available for PC, PlayStation 3, PlayStation 4, PlayStation Vita, Nintendo 3DS, Nintendo Wii U, Nintendo Switch, and Xbox One.