Tap forward twice to run.
Tap forward, forward+B (or punch if you changed the control layout) to perform your signature move.
Jump in the air in any direction, and press down+B to perform a low area attack.
Hold B, and press C to perform a quick attack behind you.
Grab the other player from behind, and press jump to fling yourself from them and into an enemy.
If you get thrown by an enemy, hold up and jump on the game pad and you'll land on your feet. Great for unleashing a devestating counter attack when the enemy doesn't expect it!
At the start menu, highlight the options part, hold down A and B on the second controller and press start on the first controller. You will then be able to choose a very easy and a very hard difficulty level, start with up to 9 lives instead of 5 and you can start on any level.