Did you like Wii Sports? Hate it? Want to marry it? You're going to feel the same about Wii Play. Play comes bundled with a Wii Remote for 10 bucks extra ($50 total), so ratchet your expectations accordingly. Like Sports, Play is a Wii Remote tech demo barely concealed by a thin layer of minigames. You've got your fishing (yank up on the Remote when you've got a bite); your cow racing (hold the Remote horizontally, tilt forward to speed up, flick upward to jump); your Duck Hunt-esque balloon-shooting game (light-gun style); your laser Pong/air hockey (move the Remote to control the paddle); and your Combat-like tank battle game, which was my favorite and the only game to use the Nunchuk controller. And then three other not terribly remarkable minigames that I don't have room to describe, but trust me--you're not missing much. Play is for people who don't really like games, and as someone who really does, that's a problem. Sure, most of these minigames are fun... for about 10 minutes. But hey, maybe your grandma will want to marry it.
Demian's either feeling incredibly generous (most are fun?) or he's got some grandma in him. The majority of these minigames are most un-fun...even if you only give them 10 minutes. I'd only give two events a halfhearted thumbs-up--and only if you're playing them with a friend. Searching for or matching up Miis in a crowd is casually entertaining (assuming you're also entertained by those games you'd find in the comics section of your newspaper). And playing 9-Ball works well with a friendly interface that lets you thrust the Wii-mote like a pool cue.
Demian pretty much nailed it. For someone who barely understands what a videogame even is (Mom!), Wii Play is probably the best playable instruction manual ever. But for anyone who's, uh, ever played a videogame, more than half of the nine minigames are about as much fun as a Remote calibration test. Still, even the suckiest games are OK in multiplayer, and, for that reason alone, it's ideal "family gathering" material.