Pros: Build your own player, linkable to play with a friend
Cons: Not quite as cool as N64 Mario Golf, not extremely challenging

I heard that Mario Golf was a great game from friends of mine who had already purchased it, so I thought I would take a chance and purchase it brand new. I ripped the game from the package and dug in, and didn't put it down for hours.
This is probably the best game ever made for the Game Boy. It has many different features including match play with a friend where you are able to link up and challenge each other to 18 holes.
One of the coolest things about this game, however, is the fact that you get to design your own golfer, naming him, and playing with him. As you gain experience by playing, you earn experience points that can be used to improve your golfers abilities. It is like an RPG Sports game, very cool!
If you are relatively new to the 11 year old Game Boy phenomenon, I most heartily recommend your next purchase for your system be Mario Golf! Many sports games for game boy are difficult to play because the small screen makes quick actions hard to follow, this is not a problem with Mario Golf, because golf is not fast moving, but I do end with this warning, it is addictive!