Custom Robo Arena Cheats

Custom Robo Arena Unlockable: Hadoron
You must defeat all 4 Greyham Boss data and Hadoron data, and you will recieve Hadoron and his parts.

Custom Robo Arena Unlockable: Carat
You must complete all Robo type Mission battles, then beat Catoreya.

Custom Robo Arena Unlockable: Minstrel
You must defeat Hajime in your classroom after he brings Saki to school.

Custom Robo Arena Unlockable: Reacquire the Ray MkII

To reacquire the Ray MkII after losing it, defeat the Robo Cup and then go speak to your character’s father at Neobrain, Inc. Upon talking to him, he will hand back the Ray MkII.

Custom Robo Arena Unlockable: Doppelganger Goods

After successfully completing twelve grudge matches, a doppelganger of your character will appear in front of your team's clubhouse, looking almost exactly like your main character. You'll be forced to fight him. Defeat him to accomplish the following.

Defeating him the first time will net you the Majel Robo, the Indigo Gun, Indigo Bomb, Indigo Pod, and Indigo Legs, as well as a pass that will allow you to access the underground. After defeating the Greybaum enemies with the boss data, you can again fight the doppelganger. This time, he will give you the Ray II Dark Robo, Ripple Laser Gun, Deva Bomb, Cerberus Pod, and Phantom Legs.

Custom Robo Arena Unlockable: The Underground

To unlock a secret area of the game called The Underground, you must first win the Robo Cub and then win twelve subsequent Grudge Matches. You must then head to your school and fight your doppelganger outside. This battle must be won.

From there, you will get an item that grants you access to The Underground, but you must first find the entrance to the Underground. The entrance is located in the town over from your hometown (to the left). Talk to the man at the southwest section of the town, and he'll grant you access.