Over the years, Luigi has developed from a simple palette swap of Mario to a very distinct character, with a significant part of his personality being centered around living in his brother's shadow. In Ennuigi, a fan game created by Josh Millard, this personality trait, combined with the nonsensical and destructive nature of the Mario Brothers' adventures, is taken to a hilarious extreme. You play as a depressed, chain smoking Luigi who wanders the Mushroom Kingdom, reflecting on his life and the choices he's made.
Millard describes the game as the product of his critical examination of the original Super Mario Bros., which has very little in the way of narrative, especially within the game itself. Ennuigi, then, acts as a possible interpretation of Luigi's thoughts on his actions in the official games as well as a variety of other subjects, and it manages to be pretty amusing in the process.
That's just one writer's opinion, though. You can play it here, and let us know what you think in the comments below.
Source: Lexaloffle Games