Digimon Rumble Arena 2 cheats and cheat codes for Gamecube

Go to the title screen and quickly press the folowing buttons.
If the codes are accepted, you will hear a sound.

Energy item: 
Press Y, Right, Down, B, L, A, R, A, Y at the title screen. 

Full Evolve meter: 
Press X, Right, A, Y, Left, B, L + R at the title screen. 

Single-hit kills:
Press Right, Up, Left, Down, A, L + R at the title screen. 

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

Diaboramon: Beat Diaboramon
He cannot digivolve.

Duskmon: Beat Duskmon
He cannot digivolve.

MaloMyotismon: Beat MaloMyotismon 
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 Black War Greymon. 

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

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

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

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