You can guarantee that if the new left and right shoulder buttons were added to the Game Boy Advance for any one reason, it was to make sure as perfect a version as possible could be made of Mario Kart.
Regarded by many as one of the best games ever made, this is the definitive version of the SNES classic, featuring the best bits from the more recent N64 update. All the control, all the characters, and all the weapons: this is the title Game Boy Advance was made for.
Best of all you can play Mario Kart: Super Circuit linked up with four players for the ultimate in portable multiplayer fun. Gaming doesnt get any better than this!