Parents have absolutely nothing to worry about. There is no violence, there is no sexual content, and there are no instances of questionable language. This game is totally clean from start to finish. If there's a more harmless game out there, I'd like someone to tell me what it is— the only thing cleaner is a video version of checkers or solitaire, probably.
Puzzle gamers will want to check it out. It's a fairly unusual game in that it's not like anything else I've played in recent memory, and most of the challenges are engaging if you can put up with the wonky camera system. A neat feature is that you can compare your scores with other people who have played the game world wide. Of course, everyone else playing the game is probably cheating, but it's still pretty neat to see how many people are playing this title in other countries.
Deaf and Hard of Hearing gamers will have no problems at all. All instructions and relevant information is presented via text, and there are no significant auditory cues since the bulk of gameplay relies on visual examination and the ability to interpret spatial and numeric relationships. No barriers to accessibility here.