The most fun you will have on Wii Play is trying out all of the wildly inconsistent minigames, one by one. It's a bore.
If you are intending to buy Wii Play for the actual game, then you should stop right in your tracks and think about it. You only have nine minigames, and some are actually somewhat entertaining, while others will make you scratch your head in confusion. For example, you get one game (Tanks; you could probably find a flash version of this game online for free) which is somewhat developed and mildly fun. Then you get a game where you choose a different Mii out of a group of Miis. You can tell me which one would be more fun; and as you can see, not much thought was put into this.
Even Tanks can't bring this package up from its already low state, as there is yet another pointless game which is a rip-off of the classic "Pong" game, and that's pretty much all it is. Pong. Gee, thanks.
You are better off buying almost any other game, unless you want possibly 10 minutes of entertainment and a Wii Remote, then I suggest you stay away from Wii Play. That's not to say its all bad, a few games are fun and entertaining, but they are so simplistic and cheap that they can't possibly make up for anything else on this disc.