There's really no content here that could be considered objectionable. Even the "violent" games (Zelda Quest, Metroid Blast, Ninja Castle) have enemies designed to look like cartoons of paper or fabric. No one dies. They just go "poof."
The best of these are the multi-player ones (Zelda, Mario Chase, Ghost Mansion, Candy Collect) where up to five players can simultaneously compete in short, simple games where the one using the Wii U pad screen hides or runs while the others follow on the big screen and use the old-style Wii remotes. Nintendo calls this "asymmetrical" play, and it's a blast at parties... but you need a lot controllers!
The game is a "must-have" with the Wii U. Nintendo designed it to demonstrate what the Wii U is capable of, and it does so very entertainingly. Sadly, few other games yet available for the Wii U showcase the system's strengths as well. So far, I like the system, but it's just not as exciting-new as the original. It's built-in TV controller functions for YouTube and Netflix are well-implemented. Also, be aware that you WILL have to perform a firmware update before you can use the system, so you need a good wireless Internet connection as it takes at least half-an-hour and must NOT be interrupted (you can wreck the system if you do).
Note that NintendoLand comes with the Deluxe Wii U (black model) but you have to buy it separately with the basic, white Wii U.