Surprisingly good...if you have people to play with
It plays well. Swinging is obviously done with the remote (there are other control schemes, but this one is the most fun). The motion controls are very good. There are a ton of modes. And you can create your own character, and earn money to customize his or her appearance and skills. It's a small, but addicting feature.
The graphics are very good for a Wii game. The only problems arise from when you close in on textures and you see they're not great. But for the most part, the game is crisp, clear and actually looks good at times. The sound is the worst part in my opinion. Plain, boring golf sounds mixed with weird thunder and funny sound effects when you smack the ball. It's strange. Also, the announcers are terrible. Absolutely horrible.
Only get this game if you have friends who like this kind of game. It's a good game itself, but utterly dull by yourself.