According to the ESRB, this game contains: Comic Mischief
Parents don't have anything to worry about. I really have no idea what "Comic Mischief" is supposed to mean, but there is no violence in the game unless you count stomping on the heads of turtles or taking out fish with a cannon that shoots bubbles. There is no sexual content or questionable language, although I do think that the developers were playing a little joke by calling the game's item a "Vibe Wand." It doesn't seem like a big deal initially, but there is a line at the end of the game that suggests "when Dad is angry and mom is smiling, the Vibe Wand might be nearby." Between that and trying to explain why Peach uses powers that turn her into an emotional train wreck, moms and dads might have a little bit of explaining to do. (And by the way, I'm only being a little sarcastic.)
Mario fans might want to check out Peach's first starring role, just don't expect too much. The game is fairly simple and over in a day or two, so although it might make for a pleasant plane ride, it's not something you will likely come back to time and time again.
Deaf and Hard of Hearing gamers won't have any problems. The game's dialogue is fully captioned and there are no significant auditory cues. I played about half of the game without any sound, and didn't notice any issues worth mentioning. It's all visual here.