IGN takes a look at Wii Play and writes up a review. The game comes packaged with a Wii Remote and retails for $49.99. Which means you are paying for the Remote and and $10 game and according to IGN its a good thing it's a $10 game.
"The price is definitely right and for good reason: Wii Play is incredibly shallow; in fact, by comparison it makes the already-flimsy Wii Sports look like a Zelda adventure in scope. Wii Play's mini-games are designed to last for minutes at a time and not hours, which is one of its shortcomings. That being true, for about the price of a movie ticket, it's much easier to forgive any of the project's weaknesses and embrace its strengths, even if they are short-lived."