Go to the OPTIONS menu and hold Up + L + R until the screen shakes. This
should allow you to access the green ? mark menu. Here you can enable
one button fatalities, normal boss damage and a few other cool tricks.
To play as Chameleon,choose any "masked" male ninja. After you have
chosen your destiny, hold Away, then press and hold Run + Block + High
Punch + High Kick. When your match starts your male masked ninja should
turn into Chameleon.