Grunty's Mansion 2.0 is most likely a fan-made game for the Nintendo 64, perhaps inspired by the Banjo-Kazooie series given the reference to 'Grunty's Mansion'. It's probable that the gameplay involves collecting items, solving puzzles, and exploring a 3D environment within the titular mansion. Specific gameplay details and information about its developers would only be found within online forums and communities dedicated to N64 ROM hacks and homebrew game development.

Grunty's Mansion 2.0

Goomba's Easter Egg Hunt