Cheat mode:
Enter JPEARCE as a name to unlock all robots, arenas,
trophies, and 9,999,999 credits.
Use any arena in free play mode:
Highlight a locked arena that is directly next to a
locked arena in free play mode. Press D-pad + X when
moving towards the locked arena. If timed correctly,
the previously locked arena will be playable.
Switch robots:
Select "War Zone" at the main menu and choose any robot.
After winning a match, the game will display your upcoming
opponent. Press Select + A to play as your opponent against
the robot that you last defeated.
Behemoth:
Win the Russian Rampage Cup.
Chaos 2:
Win the Robot Wars World Championship Tournament Cup
Diotoir:
Win the Rooftop Punishment (Japan).
Firestorm:
Win The Hamburg Heavyweight Cup.
Hypnodisc:
Win the Flip Frenzy Tournament Cup as Chaos 2.
Mortis:
Win the Liberty Lightweight Cup in the North America Arena with
a bought lightweight class robot. Mortis can now be bought for
40,000 credits.
Panic Attack:
Win the Scrapyard Challenge (Sao Paulo).
Pussycat:
Win the Alpha Viking (North Sea).
Razor:
Win The Nerves Of Steel Cup.
Terrorhurtz:
Win the Heavy Bomber (Siberia).
Thor:
Win the Robot Wars Championship Cup.
Kilamanjaro level:
Win the Robot Wars Championship (which also unlocks Chaos 2) to
unlock the bonus Kilamanjaro level.
Note: The Siberia level must already be unlocked.
Sites: