After defeating the entire game, go into versus and instead of having the regular characters, you'll have all 37 to choose from.
999% in Z Campaign Mode
When the Z ranking screen is displayed at the end of an episode hold select + triangle + square + x. Release the buttons and press up or down to change the Z rank. Raise it to 999% to view a special ending.
Android 16 in Z Mode
To get rid of Android 16 in Z Mode, simply allow him to kill SSJ Goku. Android 16 is programmed to kill Goku, and once this is done he will leave.
You can also get rid of Android 16 without letting Goku die. Simply take him off your team and add a different character and Android16 will leave.
Original Goku in the final battle against Kid Buu
First, choose Goku on your team; do not choose Vegeta yet. Let Kid Buu do his special attacks (that take off health) on you twice. When Kid Buu does his attacks, the screen will freeze briefly, then Goku will not be a Super Saiyan.
SS Goku in the battle against Freiza
Use only Goku (normal) and Krillin. Intentionally allow Krillin to die by playing as him and letting the power meter go completely in Freiza's favour. After Krillin dies three times, Goku (normal) will leave and turn into SS Goku untill Freiza is defeated and you move on to the next stage.
Soundtrack
Place the game disc in an audio CD player and play tracks two and above to hear eighteen music tracks from the game.
Using the Energy Aura
The energy aura around you character (Power Up + Up) actually increases your character's speed and strength. Use this wisely, as it burns up your energy fast. Note: The aura around Son Goku before he goes SSJ is actually the Kaio-Ken attack.
Defeating Mini Cells
When playing in adventure mode select any character and just use Gohan to defeat Cell. Once you attack him three times he will die, and all his Cell juniors will automatically leave with him.
Cell Jr. double team and triple team attacks
In story mode, when you reach the Cell Game, the Cell Jr.'s will gang up on characters for their Meteo attacks if you have two or more of the following characters (Piccolo, Vegeta, Kuririn, or Mirai no Trunks), in play at a time with a Cell Jr. highlighted as the target opponent. If two Cell Jr.'s are in play, the Meteo will be a Cell Jr. on each side of the opponent firing a KameHameHa. If three Cell Jr.'s are in play, the Meteo will be all three Cell Jr.'s firing KameHameHas that combine into a large beam and hit the opponent.
Majin Vegeta
After you kill Debura once or twice, Vegeta will appear. He will not fight with you. Kill Debura and you will move to fight Majin Buu. Select Vegeta to be on your team and he will still be a Majin.
Majin Buu on your side
In the last level where you have to fight two Majin Buus, the second time you fight him have Vegeta get hit twice. Once that happens, the fat Majin Buu will come in and will be on your side.
Perfect Cell in Z Mode
To get rid of Perfect Cell in Z Mode, take Super Saiyan Young Gohan and Goku off of your team or let Cell or Cell Junior kill them. Then, Cell will leave and you will fight all Cell Junior.