I beat Octo Expansion way before the base campaign because of how boring it was. I did end up beating the base campaign, though the levels all felt nearly the same with the addition of very few story beats you really care about outside of the beginning and end. Octo Expansion is the far superior campaign with interesting, distinct levels, a better incentive to progress with its rewards for the multiplayer that are far easier to attain, and a story with more than two moments you care about and characters that hold a sense of weight and have a relationship with the protagonist. The final boss of the campaign, the REAL final boss after you 100% all of Octo Expansion, was an extreme jump in difficulty that felt so euphoric to experience and rewarding to overcome. The base campaign's final boss was serviceable, I feel he's fine, though Octo Expansion took it to another level. Together they're three and a half stars, but Octo Expansion is 5 on its own and Splatoon 2 on its own is 2 and a half.