Remember the arena you can play in one-player mode but is normally unaccessible in two-player? Simple. When you play a two-player game, at the end of the match, hold all four action buttons and press start to return to the title screen. Then go back to 2 Player mode and have someone pick Gunrock as a character. Now when the stage select screen pops up, Voldo should be accessible right away, BUT DO NOT MOVE THE CONTROLLER EXCEPT TO PRESS A! Or else you will move to the normal 2 arenas and can't pick the hidden one.

While playing the House of The Dead 2 demo, if you complete the first training mission, a second level will be unlocked, where you have to destroy all zombies with 35 bullets and 2 lives.

In the demo of ready 2 rumble boxing, there is a way to get RUMBLE GLOVES. What you do is first hit your opponent enough so at the bottom the word rumble is spelled out. Now on the controller push the two top trigger buttons at the same time and your gloves will turn white and the guy will yell RUMBLEEEEEEEEEEE.

the Transmission Select screen, hold L+R+Down on the D-pad, choose your transmission, continue to hold until game starts for rainy weather.