Splatoon 2: Octo Expansion

Splatoon 2: Octo Expansion is an expansion for the fun team-based third-person shooter that brings an exciting single-player experience to the game. You play as Agent 008, who looks like an Octozone. She wakes up in the twilight on the station platform and remembers absolutely nothing. You have to explore 80 dubious underground testing centers, where a bunch of tasks and exciting puzzles await you.

The add-on requires the original version of Splatoon 2.