"mario kart" for GBA

I like this part:

On top of that, every Game Boy and Game Boy Color game can be played on the GBA.  That's the most games of any system.

Here's the part about multiplayer. It seems like some games allow you to share the game pak:

* Some games only require a single Game Pak to play Multiplayer
* Some games will require multiple Game Paks to play Multiplayer

Look for the GBA Link Cable icon on the Game Pak package to see if a game supports multiplayer game play, and check the game's instruction manual to see which options the game supports.

Sounds pretty sweet. It's too bad I'm trying to save my money, else I'd get one.