Just get all the lightning cards
All Charaboms
These are the locations of the Charaboms:
Andlar- 1-1
Dorako- 1-2
Marine Eel- 1-5
Kai-man- 2-1
Ligon- 2-2
Pommy- 2-5
Stegodon- 3-1
Petradon- 3-2
Beast P.- 3-5
Get Option for Mini Games:
Finish level 4-3 to get the mini-game option in the main menu
Play as Max in battle mode:
Collect all of the lightning cards in the normal game
Play as Golden Bomber in battle mode (You have to have PK Bobmer on yes):
Just win the victory at the end of the battle and even if another bomber blocks your ball, your still gold. It works the same way for the computer players.
Get mini game mode at the title screen:
Just beat the four mini games in normal mode
Get a second battle mode
Beat normal mode and you get A mode and B mode at the stage select screen in the standard battle mode. Mode A is the regular play and Mode B will allow you to access better powerups.