Maybe part of the title's problem is that virtually all of the games are ones you feel like you've seen before, whether it's busting ghosts, whacking moles, or shooting things a la Duck Hunt. If you are new to the Wii you can certainly have some fun with the mini-games, but if your system came with a Wii Sports/Wii Play title (or you went out and bought one) you've probably experienced all you need to experience of this type of mini-game.
In short, it feels like Nintendo went to the well one too many times to bring us Wii Play Motion. Additionally, to be advertising MotionPlus and MotionPlus built in devices still strikes us as odd as it seems to be fulfilling the promise that the Wii said it delivered upon initial release but apparently didn’t (having the remote truly sense how it was being manipulated). Is it great to have MotionPlus built into Wii Remotes? It is indeed, and they do function better than ones without, but other games (like Tiger Woods) highlight that fact far better than Wii Play Motion and are far more rewarding to boot.
If you have small children who love mini-games, particularly Mii-based ones, they will find this amusing for a time. Just make sure you have enough MotionPlus Wii Remotes for them all to play at once.
Wii Motion Play is rated E10+ (Everyone 10 and older) by the ESRB for Cartoon Violence.