Shortly after the game's release, Nintendo was sued by the production company of Ghostbusters, claiming that using a vacuum to suck up ghosts infringed on the movie. The case was dropped.
Luigi's Mansion was not only a launch GameCube game, but the first GameCube game ever shown. On August 24, 2000, when Nintendo showed the first demo reel for their new system, Luigi was the first thing shown. At the time he was without his backpack and it wasn't announced as an actual game, though, with popular conjecture being it was part of the newest Mario platformer.