Compared to The Year of Shadow, Luigi got almost absolutely nothing other than the previously mentioned Luigi's Mansion 2. New Super Luigi U and Dr. Luigi are literally just reskins of New Super Mario Bros. U and Dr. Mario but with Luigi as the main character instead of Mario. And in the terms of New Super Luigi U, there is virtually NOTHING changed from the main New Super Mario Bros. U game other than Luigi starring in the game and increased difficulty. Everything else? Exactly the same, they literally changed nothing. They didn't even give Luigi his own story, they just reprised the story of New Super Mario Bros. U, same levels, characters, and everything, minus Mario, of course. In contrast, Shadow did not just straight-up replace Sonic in Sonic Generations and have it be called Shadow Generations. Oh, no. They actually bundled the original Sonic Generations with an entirely new experience and story that revolves around Shadow (of course), Gerald Robotnik, and Maria. And they also created entirely new levels with unique environments and unique layouts that add brand-new, never-before-seen mechanics on top of the original mechanics. They gave Shadow his own story, own game, and own experience and didn't just have Shadow replace Sonic. It's called SONIC X SHADOW GENERATIONS for a reason: it's two standalone games bundled into one unified experience. And all of the positive reviews have shown.

The Year of Luigi flopped hard in comparison to The Year of Shadow.

Luigi? Got virtually nothing. Shadow on the other hand? A bike, standalone game, multiple collaborations, and more.