Bug: A rather infamous shortcut glitch is in Wario Stadium, where the very first hill after the starting line is high enough that if you hit it at an angle you can completely jump over the wall. This cuts off a significant portion of the track, putting the player way ahead. Then on top of that, if you turn around and hit a part of the wall just right at a good angle, it will cause you to jump back over the wall before the finish line, cutting off the full track. Do it right, and you can complete the full three laps in under 30 seconds.
Bug: In multiplayer Battle mode, you can keep shooting Green Shells over and over again which will forever bounce around the track if they don't hit a player, another shell or item, or environmental hazard. If you have enough Green Shells bouncing around, the game begins to not be able to handle all the activity and the smoke behind the shells will disappear.
