To knock down your opponent in 1 hit, go to the Z-Store and then to the Bonus Settings. Once you are in the Bonus Setting, click on "Instant Death." Then go to Tournament, and pick your character. Once you are fighting, be careful, not to get hit, cause you will die instantly. But the same thing will happen to your opponent, hit them once and they will die, not to mention that you will get a perfect every time you fight.
Android 16
Successfully complete tournament mode as Android 18.
Android 16: Moves
Energy Beam: Press Left, Right, Left, Right+B
Rocket Punch: Press Left, Down/Left, Down, Down/Right, Right, L
Broly
Successfully complete tournament made with all characters including the hidden ones.
Broly: Moves
Hover Punch-
Left, Left/Down, Down, Right/Down, Right, B.
Green Sphere-
Down, Right/Down, Right, Right/Down, Down, Left/Down, Left, R.
Seismic Punch-
Down, Left/Down, Left, Left/Down, Down, Right/Down, Right, L.
Buu
Successfully complete the tournament mode as Piccolo.
Buu-Super Punch
Use Buu on any fight. Press down, forward, b.
Cell
Successfully complete tournament mode as Android 16.
Faster Kamehameha
Play as Goku, Gotenks, or Krillin and hold the D-pad diagonally and hit B, B, B.
Frieza
Successfully complete the time challenge as vegeta.
Beat the tournament as Gohan & beat the tournament as Trunks.
Get more Z points and change difficulty level
When you go to the Z-store.Buy from the Bonus Setting and that will allow you to change the difficulty level and it will allow you to get more Z-points even faster,or allowing you for extremely challenging fighting matches.
Glitch: Broly Wave
1st, turn on the "Explosive Touch" & "Free Supers" on in the BONUS SETTINGS.
Choose Broly for any fight. Use the Hover Punch move*. After Broly gets up, the wave from his Hover Punch remains on him, but he DOES NOT continue using hover punch. To get rid of the wave, simply jump.
Glitch: Nappas Head
Unlock the characters Cell and Nappa and go to sparring with you being cell and the computer as nappa. charge until you can do the normal Kamehameha(the one where you punch him into the sky) and do it to him when you are right next to him and punch him into the air. you should see nappas head bobbing up and down on the botom of the screen.
Glitch: Vegeta Oazaru
First, set the fast clock as a bonus setting. Select Vegeta in a tournament fight. When time is nearly up, start using Vegeta's Oazaru attack. If you are using the attack when time runs out, for the rest of the match (Round 2 & 3) there will be a moon moving slowly around the screen. Note: It is pretty hard to get exactly the right timing.
Goku: Moves
Kamehemeha: Press Down, Forward, Down, Forward, L
Super Kamehemeha: Press Up, Down/Right, Down(2), L
Spirit Bomb: Rotate the D-Pad in a half circle forward, than press Up+R
Gotenks
Successfully complete the Time Challenge as Gohan.
Special Beam Cannon:
Right,Left,Diagonal,Down,Diagonal,Right+B
Rapid Fire: Down,Diagonal,Left,Down,Diagonal,Left+L
Raditz
Successfully complete tournament mode as Gohan.
Surprise Attack
Turn "Free Supers" on. Just before a fight begins, punch in the button combo for any Super Attack. Your character will unleash his/her move before your opponent can even move!
The easier way to knock out your opponent is to simply duck and kick/press are. You might get hurt though but you will be a 'quick winner'. But for doing this you must get closer to your opponent.