When you are playing, press START, then hold X button. (Try, with controller one and controller two, press START button quickly and many times during the game; you'll see a lot of letters in the screen.)
Disappearing Trick
For disappear, wait for the moment that your opponent will attack you projecting you down or up. Until that moment, hold A+Up, and your character will give a disappear and will give a punch or a kick in your opponent.
Note: this trick works better with weak enemies such as Kuririn and using fast characters like Goku, Vegeta or Picollo.
Level Select
In the title screen, press and hold X+Y+Z+START. Now you can choose the "SP battle" mode in the menu screen and you have will all the characters clear.
