Digimon Rumble Arena 2

Single-hit kills:
Go to the title screen and quickly press Right, Up, Left, Down, A, L + R
buttons on your Xbox controller. If the code is accepted you should hear
a sound.

Maximum evolve meter:
Go to the title screen and quickly press X, Right, A, Y, Left, B, L + R
buttons on your Xbox controller. If the code is accepted you should hear
a sound.

Evolve energy item:
Go to the title screen and quickly press Y, Right, Down, B, L, A, R, A, Y
buttons on your Xbox controller. If the code is accepted you should hear
a sound.

Unlockables:
Defeat the following digimons in single player mode to unlock them:

Diaboramon: Beat Diaboramon
He cannot digivolve.

Duskmon: Beat Duskmon
He cannot digivolve.

Malo Myotismon: Beat Malo Myotismon
He cannot digivolve.

Neemon: Beat Neemon
He cannot digivolve.

Omnimon: Beat Omnimon
He cannot digivolve.

Black Agumon: Beat Black Agumon
He can digivolve to Back Greymon and BlackWarGreymon.

Black Gabumon: Beat Black Gabumon
He can digivolve to BlackG arurumon and Black Metal Garurumon.

Black Guilmon: Beat Black Guilmon
He can digivolve to BlackG rowlmon and Chaos Gallantmon.

Unlock Chaos Wasteland stage:
Beat any of the following Digimon:
Duskmon, Diaboramon, Omnimon, Malo Myotismon, or Neemon.

Unlock Ice Palace stage:
Play in single player mode and defeat the Boss on bottom.