Probably an essential entry in the Wii's library. Unfortunately, it's emblematic of a lot of the Wii's library in some ways, and not just the cream of the first-party crop. Certain microgames just don't give the feedback they need to convey how they actually function. A key example is the Boss microgame for the Tiny Wario set (the "final boss" by most accounts). While it looks like the actions required are conveyed on-screen (a human figure holding a wii remote is shown performing actions you are meant to mirror, and is preceded by three other figures, such that the timing seems unambiguous), it genuinely feels like the game wants you to perform some of the actions a half second EARLIER than the visuals would suggest (doing so allowed me to pass, after many failures)(Edit: after considering this again months later, it might be the case that my current setup suffers from a critical amount of display lag).
Still, don't let that or my score deter you at all. Getting into a groove, playing a set of microgames and doing all the exaggerated motions the way Nintendo's advertising division dreamed you would is actually a lot of fun, even completely alone.