To play in a character's different costumes, Hold UP and then select your character with the A button or C button. or Hold DOWN and select your character with the A button or C button or Start button.
Press Down, Up, Right, and A + Left at the Character Selection Screen for 99 seconds of time.
Enter the options screen,then highlight the ''Exit'' selection, and tap Left until the hidden options are displayed
Hold B while highlighting player 1's life selection at the Options screen, until the message ''No Damage'' appears. Then press Start.