It’s a surprise to everybody!
The info page takes some stuff from the instruction manual and some is written for this particular port. The main thing I wanted to cover was the unstated introduction. Luigi won a mansion in a contest he didn’t enter, and that sounded suspicious as all get out, so Mario went to check it out first. When he didn’t return, Luigi set out to look for him. The plot sounds remarkably similar to the CD-i game Mario is Missing, except of course this was executed much better. This was actually the first Mario game for the GameCube!
For the fact that this mansion only popped into being when the Boos freed all the portrait ghosts, it’s surprisingly well-stocked. The money seems real enough, so at least Luigi is getting something out of this misadventure. But then the question becomes, where did all the money come from? Did the ghosts have it on them when E. Gadd turned them into portraits? (Also, that portrait process looks painful. Yes, they’re ghosts, but still.) Anyway, Luigi might not enjoy his time as a Ghostbuster, but at least he’s getting well compensated.
If the game’s Boo count can be a progress meter, then I’m over 1/5 of the way through the game. That’s roughly on par with HowLongToBeat’s estimate of 10 hours. I don’t put too much stock in their estimates, because I’ve found that my play style can render them way off, but for shorter games they tend to be a better guess. Not to say I have a problem with short games (or longer ones for that matter), but I do keep tabs on roughly how quickly I’ll get through games. Metroid games are short, Zelda games are longer, and Final Fantasy games are a lot longer. Mario games are all over the place for length. This one is on the shorter side, but there are also RPGs in the mix (though even those are on the shorter side in terms of RPGs). It’ll really depend on which game I’m playing as to how quickly I get through it.