According to the ESRB, this game contains: Violence, Blood and Gore, Partial Nudity
Parents should steer younger players clear. Although the graphics look very dated compared to other games available, there are several situations featuring explicit violence, and some of the situations may be a little intense for kids. Additionally, there is one scene halfway through the game that lets the player enter a women's shower area populated with two bathers. To be honest, I was a little bit surprised at finding such content in a Nintendo-branded game even though it's relatively short and soap suds hide the most sensitive parts. In this particular instance, the "M" rating is deserved and should be given appropriate consideration before letting children curl up with it for the weekend.
GameCube owners craving some FPS action should not be fooled by appearances. This game actually focuses a great deal on solving puzzles relating to the main character's ghostly status with shooting segments being relatively few and far between. In any event, the quality of the shooting action is subpar hand adrenaline junkies would be better served with another title.
However, people who can appreciate old-school linear puzzle-solving will find more than a few clever or humorous situations. I know there are more recent examples, but the first game that leaps to mind is actually Shadowgate in terms of comparison.
Deaf and Hard of Hearing gamers have access to subtitles that accompany all spoken dialogue, and there are no significant auditory cues during gameplay except for the occasional bit of gunfire.