Hmmmm, if you like Samurai boy....
Who is the boss?
There is a 'regular attack' button, a 'strong attack' button, a 'kick' button, and a 'guard' button.
You can use these in combination with the joystick (or D-Pad, whichever you use) to do different moves. You'll find that forward + strong attack is useful against slow opponents.
Guard + Regular Attack can be used to grab your opponents when you are close to them.
On the gamecube, the c-pad does a bunch of different powerful moves...don't know what the controls are for PS2.
Check out
http://www.gamefaqs.com I bet they have more in depth info.