Unlock Big Zam:
Beat Time Attack under 5 minutes to unlock the Big Zam in Versus, Time Attack, and Survival Modes.
Unlock Master Gundam:
Clear Street Mode on Hard difficulty using Burning Gundam and Gundam Maxter.
Unlock Niue Zeil:
Play Survival mode until you earn 22 victories to unlock Niue Zeil in Versus, Time Attack and Survival Modes.
Unlock Phyco Gundam:
The easiest way to pass Time Attack Mode B is to use Gundam GP-02A and press DOWN, BACK + PUNCH very close to the opponent. Cheesy, but effective.
Unlock Secret Gundams In Versus, Time, & Survival Modes:
Play as Master Gundam in Street Mode to unlock Dark Gundam, Master Gundam, Quin Mantha, and Gundam Epyon in Versus, Time Attack, and and Survival mode.
Alternate color:
At the title screan hold R1 and press start.