Xenophage

Type these codes in on the battle screen Some will actually make the
game more challenging, rather than easier, which is a refreshing change
of pace here.

bishop Summons the Apogee announcer
blood Increases game gore
glassjaw One blow stun mode for both fighters
helium Different gravity
invisible Both fighters are invisible
shadows Shadows only
stain More game blood

These codes must be entered on the menu screen:

xacman Hidden mini game
champs Choose any Champion as your fighter (Reg. ver. only) (Information from Cheat Machine)