Splatoon Raiders is the first what for the Splatoon series?

Splatoon Raiders is the first spinoff for the Splatoon series.

The game expands the franchise beyond its established mainline entries. Earlier Splatoon titles centered heavily on competitive multiplayer, with single-player campaigns and modes supporting that broader formula. Raiders instead presents a primarily single-player, story-focused adventure built around island exploration, salvage, treasure hunting, and repeated combat expeditions.

Its spinoff status also explains several changes in structure and setting. The game introduces a new protagonist known as the Mechanic, places the story in the Spirhalite Islands, and features Deep Cut as companions. Those elements let Nintendo explore a different genre and tone without replacing the core series format.

The answer is not “expansion”: an expansion adds substantial content to an existing game, while Raiders is a separate release. It is also not a remake or compilation, because it presents a new adventure rather than reproducing or bundling earlier Splatoon games.